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Jeff Lane
03-09-2001, 02:40 PM
This will probably look (and be) a trifle disjointed, because it is a collection of letters to WoodButcher on the subject. It describes a fairly slow and primative method of making trenails when there is no real trenail lathe available. It is, however, pretty effective, when you get going with it. I suppose it is good for about fifteen trenails an hour, at best. (A real trenail lathe turns out about two to four per minute).
I also describe here the way I install trenails, which I have found to be pretty good, over the years. I've never seen that one I put in has rotted, regardless of the wood used:

To make trenails, when you don't have a proper trenail lathe: Saw square blanks about 1/4" bigger than you need the barrels to be. The barrels should be about 3/4" to 7/8" diameter for 3" sided single or double-sawn frames, as WoodButcher will probably use. (I use
11/8" diameter greenheart trenails in my 2" oak planking on Gladhval, as she has 5 1/2' double-sawn frames.) Use hardwood, if you will put them into oak or other hard planking. Locust or oak are probably about the best available near you, WoodButcher.
Make the blanks about 8" longer than you need them to be. You probably need around two thousand of them, for a vessel like "Sunrise". Raise a large tabletop joiner (planer) blade up about 1/8", and run the blank over it to within about 5" of the end (clamp a stop on the table). Run them on four sides. Now, raise the planer blade so that when you run them on the corners, the thickness of the barrel turns out the same across all the flats. Run all four corners. Now they are eight-sided, with square heads. Now, change the blade height again, to a height that, when you plane the corners of the head, the distance across the flats is the same for the original flats and the newly-planed ones. Now the head is also eight-sided. Alternatively, you could have made the blanks eight-sided to begin with.

At this point you can finish the sixteen corners with a spoke shave, or a little belt sander, or a draw knife, or the planer, using the same system as before on all the sixteen corners. You don't have to finish the heads; Just the barrels, and they don't have to be absolutely round, but pretty close. The diameter of a large planer blade will form a fairly good radius from the barrel up to the head. Drill the holes about one millimeter too small, and try it in a block of hardwood first. It should go with a little difficulty, but not risk either splitting the block, or breaking.

Chamfer the trenail on the end so it doesn't hang up on anything in the hole, chamfer the hole in the planking to accept the trenail. The ideal planking chamfer/trenail head flare would be as follows, but you can't do that on a planer:
The chamfer in the planking hole, and the flare at the trenail head, should be as long into the hole as possible, up to about 1/3 of the planking thickness.
It shouldn't be particulary large in diameter; A chamfer angle of, say, 15 degrees, (as opposed to the normal chamfer angle of 45 degrees used on most machine work), would be about right. In Norway that is done not with a straight chamfer, but with a gently curving one, but it doesn't matter what shape you use as long as the angle is roughly as described. The trenail chamfer, and that of the plank, should correspond. A "golf tee"-type shape would be pretty good.

Make wedges that are the diameter of the barrel of the trenail, about 4" long, and about 1/4" thick at the big end, sharp at the other. Make them out of locust, or greenheart, juniper, purple heart, or even oak. When the plank is steamed and clamped in place, drill the holes, swab them with a 50-50 mixture of raw linseed oil and Cuprinol of a sort compatible with the metal fastenings in the area, and put in trenails as soon as possible, while the plank is still hot and wet, if you can. (Saves the risk of splitting the plank). Paint them first with the mixture, as you go. Drive all of the trenails, go back over them to be sure the plank is solidly down on the frames with a 7-pound hammer or bigger, saw off the inside end of the trenail flush with the frame, or stringer, for those that go through stringers, take a chisle the width of the diameter of the trenail and deeply mark the inside end of the trenail in a direction perpendicular to the grain of the innermost piece of wood the trenail goes through, paint the Cuprinol/raw linseed oil mixture on the end of the trenail and on the wedge, and drive the wedge in about
2 1/2" or so. saw it off flush with the frame. Paint the raw end again. Do that with all the trenails on the plank, then go out and seat them one more time with the hammer, being very careful not to start split marks in the plank. Make pyramidal wedges about 3" in length, by sawing a 4" square block of the same hardwood first one way on the bandsaw for all the wedges the block has room for, then rotating it 90 degrees and sawing the wedges again from that direction. (Half of the resulting pieces you must throw away, as they aren't pyramids.) Saw the heads off, and paint them with the mixture. Drive a big spike, sharpened to a square-cross-sectional point, and deeply mark the center of the sawn trenail head, paint the hole, and the pyramid, and drive the wedge in about 3/4 the thickness of the plank with a small hammer. Saw the wedge off flush and paint the end.

You've trenailed your first plank, congratulations. I hope you didn't split it, that you got it down everywhere on all the frames, and that the result looks and is good. That's how I do the business, when I can't find a real trenail lathe. You can also, of course, turn them on a wood lathe, but it usually takes a little longer. They come out rounder, though. A real, old-fashioned Norwegian-type trenail lathe makes several trenails per minute.

The radius at the head is critical; That's what holds the plank on, other than friction, so the radius should be as large as possible, so it won't be too abrupt and split off easily. I'd stick to traditional trenails, and not glued ones, as Ian mentioned...You might want to remove a plank some day, for some reason. Do it right, fit them tightly and well, and they will be a perfect fastener. They don't tend to rust, and made and installed like I say, they don't rot either.

The trenail blank heads should be at least 5" long, outside the plank. If you make them longer, they are easier to control the direction of while planing, and therefore the barrel diameter accuracy is improved. It just depends on how much wood you are willing to eventually waste, as the heads are cut off flush with the planking when the chamfer is seated into it's planking recess. The length of the trenail, from the flare at the planking surface to the end of the trenail before it is sawn off flush with the inside of the frame, or stringer, or whatever it goes through, should be about three inches longer than the distance from the plank outer surface to the inside surface of what it must go through. You should saw off about 3" on the inside, and nearly the whole head of the trenail, except for the flare which is in the planking chamfer, to finish the trenail when it is installed.

If you push trenails through a hole sizer, as someone also mentioned earlier on this forum, you must do something pretty clever about the radiused flare at the head. You need that, and it must be smooth. I make that radius as accurate as I can, and then rub a ring of SikaFlex 11FC around the flare, and also one into the chamfer, before it seats, to ensure a good watertight seal.

Answers To A Few Questions Asked By e-mail Lately:

1. It doesn't really matter how much bigger the head of the trenail is than the barrel, since you will be cutting it off anyway. What matters is that it is big enough to fill the chamfer cutout in the outside of the hole in the plank. I usually make the heads about 1/4" bigger than the barrels, and that is slightly more than enough to fill a healthy chamfer in the plank.

2. The trenail barrels aren't tapered, at least not in Norway. If they were, and worked slightly out of the plank, even a millimeter, they would then be looser. As I said in the above, they are straight, with no taper, and they are put in with a slight interference fit, about one millimeter. They should go in hard, but not hard enough to split the plank.
This taper business is perhaps a "Ford vs. Chevy" traditional thing. The only trenails I have had to do with, (Quite a few, by now), have been either Norwegian or mine, and my trenail education is from dealing with Norwegian boats.

Just an aside: Norwegian square, galvanized boat nails are tapered on two sides. Danish square, galvanized boat nails are straight all the way, and the Danes claim that is better because if the nail is backed out slightly, they fear it will loosen, like both countries claim about trenails. It is true that a Danish boat nail comes out with very slightly more difficulty than a Norwegian one, after the nail is first pulled back about
1/4", but until that point the friction is about the same. Norwegians claim that the initial friction is greater, with the nails tapered on two sides. Both nail types have good holding qualities, so it doesn't matter. Both countries use straight, untapered trenails, though.

3. Your frames, as I said, should be at least 3" sided, so as to avoid splitting when the trenails are put in.

4. A normal wood lathe is not the quickest way to make trenails, although with the modifications that one of the posters on the forum gives, it may be reworked to be pretty good. Normal turning methods are very slow, though, so look closely at his modifications for the lathe...that sounds not bad at all.

Jeff Lane
jeff.lane@hl.telia.no



[This message has been edited by Jeff Lane (edited 03-09-2001).]

Jeff Lane
03-09-2001, 02:40 PM
This will probably look (and be) a trifle disjointed, because it is a collection of letters to WoodButcher on the subject. It describes a fairly slow and primative method of making trenails when there is no real trenail lathe available. It is, however, pretty effective, when you get going with it. I suppose it is good for about fifteen trenails an hour, at best. (A real trenail lathe turns out about two to four per minute).
I also describe here the way I install trenails, which I have found to be pretty good, over the years. I've never seen that one I put in has rotted, regardless of the wood used:

To make trenails, when you don't have a proper trenail lathe: Saw square blanks about 1/4" bigger than you need the barrels to be. The barrels should be about 3/4" to 7/8" diameter for 3" sided single or double-sawn frames, as WoodButcher will probably use. (I use
11/8" diameter greenheart trenails in my 2" oak planking on Gladhval, as she has 5 1/2' double-sawn frames.) Use hardwood, if you will put them into oak or other hard planking. Locust or oak are probably about the best available near you, WoodButcher.
Make the blanks about 8" longer than you need them to be. You probably need around two thousand of them, for a vessel like "Sunrise". Raise a large tabletop joiner (planer) blade up about 1/8", and run the blank over it to within about 5" of the end (clamp a stop on the table). Run them on four sides. Now, raise the planer blade so that when you run them on the corners, the thickness of the barrel turns out the same across all the flats. Run all four corners. Now they are eight-sided, with square heads. Now, change the blade height again, to a height that, when you plane the corners of the head, the distance across the flats is the same for the original flats and the newly-planed ones. Now the head is also eight-sided. Alternatively, you could have made the blanks eight-sided to begin with.

At this point you can finish the sixteen corners with a spoke shave, or a little belt sander, or a draw knife, or the planer, using the same system as before on all the sixteen corners. You don't have to finish the heads; Just the barrels, and they don't have to be absolutely round, but pretty close. The diameter of a large planer blade will form a fairly good radius from the barrel up to the head. Drill the holes about one millimeter too small, and try it in a block of hardwood first. It should go with a little difficulty, but not risk either splitting the block, or breaking.

Chamfer the trenail on the end so it doesn't hang up on anything in the hole, chamfer the hole in the planking to accept the trenail. The ideal planking chamfer/trenail head flare would be as follows, but you can't do that on a planer:
The chamfer in the planking hole, and the flare at the trenail head, should be as long into the hole as possible, up to about 1/3 of the planking thickness.
It shouldn't be particulary large in diameter; A chamfer angle of, say, 15 degrees, (as opposed to the normal chamfer angle of 45 degrees used on most machine work), would be about right. In Norway that is done not with a straight chamfer, but with a gently curving one, but it doesn't matter what shape you use as long as the angle is roughly as described. The trenail chamfer, and that of the plank, should correspond. A "golf tee"-type shape would be pretty good.

Make wedges that are the diameter of the barrel of the trenail, about 4" long, and about 1/4" thick at the big end, sharp at the other. Make them out of locust, or greenheart, juniper, purple heart, or even oak. When the plank is steamed and clamped in place, drill the holes, swab them with a 50-50 mixture of raw linseed oil and Cuprinol of a sort compatible with the metal fastenings in the area, and put in trenails as soon as possible, while the plank is still hot and wet, if you can. (Saves the risk of splitting the plank). Paint them first with the mixture, as you go. Drive all of the trenails, go back over them to be sure the plank is solidly down on the frames with a 7-pound hammer or bigger, saw off the inside end of the trenail flush with the frame, or stringer, for those that go through stringers, take a chisle the width of the diameter of the trenail and deeply mark the inside end of the trenail in a direction perpendicular to the grain of the innermost piece of wood the trenail goes through, paint the Cuprinol/raw linseed oil mixture on the end of the trenail and on the wedge, and drive the wedge in about
2 1/2" or so. saw it off flush with the frame. Paint the raw end again. Do that with all the trenails on the plank, then go out and seat them one more time with the hammer, being very careful not to start split marks in the plank. Make pyramidal wedges about 3" in length, by sawing a 4" square block of the same hardwood first one way on the bandsaw for all the wedges the block has room for, then rotating it 90 degrees and sawing the wedges again from that direction. (Half of the resulting pieces you must throw away, as they aren't pyramids.) Saw the heads off, and paint them with the mixture. Drive a big spike, sharpened to a square-cross-sectional point, and deeply mark the center of the sawn trenail head, paint the hole, and the pyramid, and drive the wedge in about 3/4 the thickness of the plank with a small hammer. Saw the wedge off flush and paint the end.

You've trenailed your first plank, congratulations. I hope you didn't split it, that you got it down everywhere on all the frames, and that the result looks and is good. That's how I do the business, when I can't find a real trenail lathe. You can also, of course, turn them on a wood lathe, but it usually takes a little longer. They come out rounder, though. A real, old-fashioned Norwegian-type trenail lathe makes several trenails per minute.

The radius at the head is critical; That's what holds the plank on, other than friction, so the radius should be as large as possible, so it won't be too abrupt and split off easily. I'd stick to traditional trenails, and not glued ones, as Ian mentioned...You might want to remove a plank some day, for some reason. Do it right, fit them tightly and well, and they will be a perfect fastener. They don't tend to rust, and made and installed like I say, they don't rot either.

The trenail blank heads should be at least 5" long, outside the plank. If you make them longer, they are easier to control the direction of while planing, and therefore the barrel diameter accuracy is improved. It just depends on how much wood you are willing to eventually waste, as the heads are cut off flush with the planking when the chamfer is seated into it's planking recess. The length of the trenail, from the flare at the planking surface to the end of the trenail before it is sawn off flush with the inside of the frame, or stringer, or whatever it goes through, should be about three inches longer than the distance from the plank outer surface to the inside surface of what it must go through. You should saw off about 3" on the inside, and nearly the whole head of the trenail, except for the flare which is in the planking chamfer, to finish the trenail when it is installed.

If you push trenails through a hole sizer, as someone also mentioned earlier on this forum, you must do something pretty clever about the radiused flare at the head. You need that, and it must be smooth. I make that radius as accurate as I can, and then rub a ring of SikaFlex 11FC around the flare, and also one into the chamfer, before it seats, to ensure a good watertight seal.

Answers To A Few Questions Asked By e-mail Lately:

1. It doesn't really matter how much bigger the head of the trenail is than the barrel, since you will be cutting it off anyway. What matters is that it is big enough to fill the chamfer cutout in the outside of the hole in the plank. I usually make the heads about 1/4" bigger than the barrels, and that is slightly more than enough to fill a healthy chamfer in the plank.

2. The trenail barrels aren't tapered, at least not in Norway. If they were, and worked slightly out of the plank, even a millimeter, they would then be looser. As I said in the above, they are straight, with no taper, and they are put in with a slight interference fit, about one millimeter. They should go in hard, but not hard enough to split the plank.
This taper business is perhaps a "Ford vs. Chevy" traditional thing. The only trenails I have had to do with, (Quite a few, by now), have been either Norwegian or mine, and my trenail education is from dealing with Norwegian boats.

Just an aside: Norwegian square, galvanized boat nails are tapered on two sides. Danish square, galvanized boat nails are straight all the way, and the Danes claim that is better because if the nail is backed out slightly, they fear it will loosen, like both countries claim about trenails. It is true that a Danish boat nail comes out with very slightly more difficulty than a Norwegian one, after the nail is first pulled back about
1/4", but until that point the friction is about the same. Norwegians claim that the initial friction is greater, with the nails tapered on two sides. Both nail types have good holding qualities, so it doesn't matter. Both countries use straight, untapered trenails, though.

3. Your frames, as I said, should be at least 3" sided, so as to avoid splitting when the trenails are put in.

4. A normal wood lathe is not the quickest way to make trenails, although with the modifications that one of the posters on the forum gives, it may be reworked to be pretty good. Normal turning methods are very slow, though, so look closely at his modifications for the lathe...that sounds not bad at all.

Jeff Lane
jeff.lane@hl.telia.no



[This message has been edited by Jeff Lane (edited 03-09-2001).]

Jeff Lane
03-09-2001, 02:40 PM
This will probably look (and be) a trifle disjointed, because it is a collection of letters to WoodButcher on the subject. It describes a fairly slow and primative method of making trenails when there is no real trenail lathe available. It is, however, pretty effective, when you get going with it. I suppose it is good for about fifteen trenails an hour, at best. (A real trenail lathe turns out about two to four per minute).
I also describe here the way I install trenails, which I have found to be pretty good, over the years. I've never seen that one I put in has rotted, regardless of the wood used:

To make trenails, when you don't have a proper trenail lathe: Saw square blanks about 1/4" bigger than you need the barrels to be. The barrels should be about 3/4" to 7/8" diameter for 3" sided single or double-sawn frames, as WoodButcher will probably use. (I use
11/8" diameter greenheart trenails in my 2" oak planking on Gladhval, as she has 5 1/2' double-sawn frames.) Use hardwood, if you will put them into oak or other hard planking. Locust or oak are probably about the best available near you, WoodButcher.
Make the blanks about 8" longer than you need them to be. You probably need around two thousand of them, for a vessel like "Sunrise". Raise a large tabletop joiner (planer) blade up about 1/8", and run the blank over it to within about 5" of the end (clamp a stop on the table). Run them on four sides. Now, raise the planer blade so that when you run them on the corners, the thickness of the barrel turns out the same across all the flats. Run all four corners. Now they are eight-sided, with square heads. Now, change the blade height again, to a height that, when you plane the corners of the head, the distance across the flats is the same for the original flats and the newly-planed ones. Now the head is also eight-sided. Alternatively, you could have made the blanks eight-sided to begin with.

At this point you can finish the sixteen corners with a spoke shave, or a little belt sander, or a draw knife, or the planer, using the same system as before on all the sixteen corners. You don't have to finish the heads; Just the barrels, and they don't have to be absolutely round, but pretty close. The diameter of a large planer blade will form a fairly good radius from the barrel up to the head. Drill the holes about one millimeter too small, and try it in a block of hardwood first. It should go with a little difficulty, but not risk either splitting the block, or breaking.

Chamfer the trenail on the end so it doesn't hang up on anything in the hole, chamfer the hole in the planking to accept the trenail. The ideal planking chamfer/trenail head flare would be as follows, but you can't do that on a planer:
The chamfer in the planking hole, and the flare at the trenail head, should be as long into the hole as possible, up to about 1/3 of the planking thickness.
It shouldn't be particulary large in diameter; A chamfer angle of, say, 15 degrees, (as opposed to the normal chamfer angle of 45 degrees used on most machine work), would be about right. In Norway that is done not with a straight chamfer, but with a gently curving one, but it doesn't matter what shape you use as long as the angle is roughly as described. The trenail chamfer, and that of the plank, should correspond. A "golf tee"-type shape would be pretty good.

Make wedges that are the diameter of the barrel of the trenail, about 4" long, and about 1/4" thick at the big end, sharp at the other. Make them out of locust, or greenheart, juniper, purple heart, or even oak. When the plank is steamed and clamped in place, drill the holes, swab them with a 50-50 mixture of raw linseed oil and Cuprinol of a sort compatible with the metal fastenings in the area, and put in trenails as soon as possible, while the plank is still hot and wet, if you can. (Saves the risk of splitting the plank). Paint them first with the mixture, as you go. Drive all of the trenails, go back over them to be sure the plank is solidly down on the frames with a 7-pound hammer or bigger, saw off the inside end of the trenail flush with the frame, or stringer, for those that go through stringers, take a chisle the width of the diameter of the trenail and deeply mark the inside end of the trenail in a direction perpendicular to the grain of the innermost piece of wood the trenail goes through, paint the Cuprinol/raw linseed oil mixture on the end of the trenail and on the wedge, and drive the wedge in about
2 1/2" or so. saw it off flush with the frame. Paint the raw end again. Do that with all the trenails on the plank, then go out and seat them one more time with the hammer, being very careful not to start split marks in the plank. Make pyramidal wedges about 3" in length, by sawing a 4" square block of the same hardwood first one way on the bandsaw for all the wedges the block has room for, then rotating it 90 degrees and sawing the wedges again from that direction. (Half of the resulting pieces you must throw away, as they aren't pyramids.) Saw the heads off, and paint them with the mixture. Drive a big spike, sharpened to a square-cross-sectional point, and deeply mark the center of the sawn trenail head, paint the hole, and the pyramid, and drive the wedge in about 3/4 the thickness of the plank with a small hammer. Saw the wedge off flush and paint the end.

You've trenailed your first plank, congratulations. I hope you didn't split it, that you got it down everywhere on all the frames, and that the result looks and is good. That's how I do the business, when I can't find a real trenail lathe. You can also, of course, turn them on a wood lathe, but it usually takes a little longer. They come out rounder, though. A real, old-fashioned Norwegian-type trenail lathe makes several trenails per minute.

The radius at the head is critical; That's what holds the plank on, other than friction, so the radius should be as large as possible, so it won't be too abrupt and split off easily. I'd stick to traditional trenails, and not glued ones, as Ian mentioned...You might want to remove a plank some day, for some reason. Do it right, fit them tightly and well, and they will be a perfect fastener. They don't tend to rust, and made and installed like I say, they don't rot either.

The trenail blank heads should be at least 5" long, outside the plank. If you make them longer, they are easier to control the direction of while planing, and therefore the barrel diameter accuracy is improved. It just depends on how much wood you are willing to eventually waste, as the heads are cut off flush with the planking when the chamfer is seated into it's planking recess. The length of the trenail, from the flare at the planking surface to the end of the trenail before it is sawn off flush with the inside of the frame, or stringer, or whatever it goes through, should be about three inches longer than the distance from the plank outer surface to the inside surface of what it must go through. You should saw off about 3" on the inside, and nearly the whole head of the trenail, except for the flare which is in the planking chamfer, to finish the trenail when it is installed.

If you push trenails through a hole sizer, as someone also mentioned earlier on this forum, you must do something pretty clever about the radiused flare at the head. You need that, and it must be smooth. I make that radius as accurate as I can, and then rub a ring of SikaFlex 11FC around the flare, and also one into the chamfer, before it seats, to ensure a good watertight seal.

Answers To A Few Questions Asked By e-mail Lately:

1. It doesn't really matter how much bigger the head of the trenail is than the barrel, since you will be cutting it off anyway. What matters is that it is big enough to fill the chamfer cutout in the outside of the hole in the plank. I usually make the heads about 1/4" bigger than the barrels, and that is slightly more than enough to fill a healthy chamfer in the plank.

2. The trenail barrels aren't tapered, at least not in Norway. If they were, and worked slightly out of the plank, even a millimeter, they would then be looser. As I said in the above, they are straight, with no taper, and they are put in with a slight interference fit, about one millimeter. They should go in hard, but not hard enough to split the plank.
This taper business is perhaps a "Ford vs. Chevy" traditional thing. The only trenails I have had to do with, (Quite a few, by now), have been either Norwegian or mine, and my trenail education is from dealing with Norwegian boats.

Just an aside: Norwegian square, galvanized boat nails are tapered on two sides. Danish square, galvanized boat nails are straight all the way, and the Danes claim that is better because if the nail is backed out slightly, they fear it will loosen, like both countries claim about trenails. It is true that a Danish boat nail comes out with very slightly more difficulty than a Norwegian one, after the nail is first pulled back about
1/4", but until that point the friction is about the same. Norwegians claim that the initial friction is greater, with the nails tapered on two sides. Both nail types have good holding qualities, so it doesn't matter. Both countries use straight, untapered trenails, though.

3. Your frames, as I said, should be at least 3" sided, so as to avoid splitting when the trenails are put in.

4. A normal wood lathe is not the quickest way to make trenails, although with the modifications that one of the posters on the forum gives, it may be reworked to be pretty good. Normal turning methods are very slow, though, so look closely at his modifications for the lathe...that sounds not bad at all.

Jeff Lane
jeff.lane@hl.telia.no



[This message has been edited by Jeff Lane (edited 03-09-2001).]

Ian McColgin
03-09-2001, 03:01 PM
These guys work too hard.

Ian McColgin
03-09-2001, 03:01 PM
These guys work too hard.

Ian McColgin
03-09-2001, 03:01 PM
These guys work too hard.

Jeff Lane
03-09-2001, 03:51 PM
What took you so long, Ian?
By "These Guys", I suppose you mean me.....

In defense of the book I posted to start this thread, I would say that it doesn't take nearly as long to do the above as it does to tell someone else how to do it.
I just thought I'd make it as clear as possible; There are reasons for every step in the process, although I didn't bore you with most of them.

Your method, I believe, makes trenails without heads, by pushing them through a steel die. (Please correct me if I'm wrong.) Somebody's does, anyway. By not having a head, set in a chamfered hole, you don't get the "setting" action that the headed trenail gives the plank, insuring a good fit of the plank down on the frame.

Also, if you ever find occasion to remove a plank from a carvel boat with glued-in trenails, I think that will probably cure you of gluing them in ever again.

Somebody else said earlier that they removed trenails by carefully drilling them out. I do that too, when I can't avoid it, but usually if you take a drive pin just a bit smaller than the barrel of the trenail, dead flat on the end, and lambaste it from the inside of the boat outward with a hammer of at least seven pounds, (preferably ten, and have somebody else hold the pin with a pair of vise-grips), you will start it out. If you don't start it the first one or two hits, forget it and drill it out like the man says.

Cheers, Jeff Lane

Jeff Lane
03-09-2001, 03:51 PM
What took you so long, Ian?
By "These Guys", I suppose you mean me.....

In defense of the book I posted to start this thread, I would say that it doesn't take nearly as long to do the above as it does to tell someone else how to do it.
I just thought I'd make it as clear as possible; There are reasons for every step in the process, although I didn't bore you with most of them.

Your method, I believe, makes trenails without heads, by pushing them through a steel die. (Please correct me if I'm wrong.) Somebody's does, anyway. By not having a head, set in a chamfered hole, you don't get the "setting" action that the headed trenail gives the plank, insuring a good fit of the plank down on the frame.

Also, if you ever find occasion to remove a plank from a carvel boat with glued-in trenails, I think that will probably cure you of gluing them in ever again.

Somebody else said earlier that they removed trenails by carefully drilling them out. I do that too, when I can't avoid it, but usually if you take a drive pin just a bit smaller than the barrel of the trenail, dead flat on the end, and lambaste it from the inside of the boat outward with a hammer of at least seven pounds, (preferably ten, and have somebody else hold the pin with a pair of vise-grips), you will start it out. If you don't start it the first one or two hits, forget it and drill it out like the man says.

Cheers, Jeff Lane

Jeff Lane
03-09-2001, 03:51 PM
What took you so long, Ian?
By "These Guys", I suppose you mean me.....

In defense of the book I posted to start this thread, I would say that it doesn't take nearly as long to do the above as it does to tell someone else how to do it.
I just thought I'd make it as clear as possible; There are reasons for every step in the process, although I didn't bore you with most of them.

Your method, I believe, makes trenails without heads, by pushing them through a steel die. (Please correct me if I'm wrong.) Somebody's does, anyway. By not having a head, set in a chamfered hole, you don't get the "setting" action that the headed trenail gives the plank, insuring a good fit of the plank down on the frame.

Also, if you ever find occasion to remove a plank from a carvel boat with glued-in trenails, I think that will probably cure you of gluing them in ever again.

Somebody else said earlier that they removed trenails by carefully drilling them out. I do that too, when I can't avoid it, but usually if you take a drive pin just a bit smaller than the barrel of the trenail, dead flat on the end, and lambaste it from the inside of the boat outward with a hammer of at least seven pounds, (preferably ten, and have somebody else hold the pin with a pair of vise-grips), you will start it out. If you don't start it the first one or two hits, forget it and drill it out like the man says.

Cheers, Jeff Lane

Ron Williamson
03-09-2001, 05:55 PM
Now that's a job for a guy with chainmail gloves.

Ron Williamson
03-09-2001, 05:55 PM
Now that's a job for a guy with chainmail gloves.

Ron Williamson
03-09-2001, 05:55 PM
Now that's a job for a guy with chainmail gloves.

woodbutch
03-10-2001, 07:46 AM
Well worth printing out, as I did :)

This is way too much work if you only want a
boat that will last ten years or so,

if you want/need it to last longer that is another story, I think this is the way to go.

woodbutch
03-10-2001, 07:46 AM
Well worth printing out, as I did :)

This is way too much work if you only want a
boat that will last ten years or so,

if you want/need it to last longer that is another story, I think this is the way to go.

woodbutch
03-10-2001, 07:46 AM
Well worth printing out, as I did :)

This is way too much work if you only want a
boat that will last ten years or so,

if you want/need it to last longer that is another story, I think this is the way to go.

Ian McColgin
03-11-2001, 06:50 AM
I think it depends on the intended use. The method Jeff shows has applications but it seems to me in boats a straight trenel has the advantage of surely putting it's diameter where it matters - where the plank meets the frame. In non-glue applications, any problems of holding it in can be met with a blind wedge on the inside and a wedge on the outside.

But, different boats, different long splices.

Ian McColgin
03-11-2001, 06:50 AM
I think it depends on the intended use. The method Jeff shows has applications but it seems to me in boats a straight trenel has the advantage of surely putting it's diameter where it matters - where the plank meets the frame. In non-glue applications, any problems of holding it in can be met with a blind wedge on the inside and a wedge on the outside.

But, different boats, different long splices.

Ian McColgin
03-11-2001, 06:50 AM
I think it depends on the intended use. The method Jeff shows has applications but it seems to me in boats a straight trenel has the advantage of surely putting it's diameter where it matters - where the plank meets the frame. In non-glue applications, any problems of holding it in can be met with a blind wedge on the inside and a wedge on the outside.

But, different boats, different long splices.

Jeff Lane
03-11-2001, 02:47 PM
Pardon me, Ian, but that doesn't seem correct to me. "Putting its diameter where it matters"? A trenail without a head has hardly any inclination to force the plank in against the frame at all, as compared with a trenail with a head, engaging a shaped, chamfered recess in the plank. When you put a conical or pyramidal wedge in the outside of the sawn-off trenail, it can flare the end out, yes, and I do that as well with headed trenails. Doing that on a straight trenail will hold the plank on, yes, especially if the plank has a deeply chamfered recess. However, because there is little or no positive force inward against the plank/frame joint, a straight trenail certainly won't force the plank in against the frame, at least not nearly as well as when a headed trenail seats into its chamfered recess, at the business end of a big hammer. Trenails are always wedged inside the boat, as I described, or should be.
As far as your comment about "...working too hard.", I can only say that it is very often the case in this boat business that excellence costs time and effort. Cheaper, easier methods that are "...just as good..." are very, very seldom things, and so it is in this case as well. At least on normal carvel planking, it is best to spend the extra effort and do it right. The results will prove that, eventually.

Jeff Lane

Jeff Lane
03-11-2001, 02:47 PM
Pardon me, Ian, but that doesn't seem correct to me. "Putting its diameter where it matters"? A trenail without a head has hardly any inclination to force the plank in against the frame at all, as compared with a trenail with a head, engaging a shaped, chamfered recess in the plank. When you put a conical or pyramidal wedge in the outside of the sawn-off trenail, it can flare the end out, yes, and I do that as well with headed trenails. Doing that on a straight trenail will hold the plank on, yes, especially if the plank has a deeply chamfered recess. However, because there is little or no positive force inward against the plank/frame joint, a straight trenail certainly won't force the plank in against the frame, at least not nearly as well as when a headed trenail seats into its chamfered recess, at the business end of a big hammer. Trenails are always wedged inside the boat, as I described, or should be.
As far as your comment about "...working too hard.", I can only say that it is very often the case in this boat business that excellence costs time and effort. Cheaper, easier methods that are "...just as good..." are very, very seldom things, and so it is in this case as well. At least on normal carvel planking, it is best to spend the extra effort and do it right. The results will prove that, eventually.

Jeff Lane

Jeff Lane
03-11-2001, 02:47 PM
Pardon me, Ian, but that doesn't seem correct to me. "Putting its diameter where it matters"? A trenail without a head has hardly any inclination to force the plank in against the frame at all, as compared with a trenail with a head, engaging a shaped, chamfered recess in the plank. When you put a conical or pyramidal wedge in the outside of the sawn-off trenail, it can flare the end out, yes, and I do that as well with headed trenails. Doing that on a straight trenail will hold the plank on, yes, especially if the plank has a deeply chamfered recess. However, because there is little or no positive force inward against the plank/frame joint, a straight trenail certainly won't force the plank in against the frame, at least not nearly as well as when a headed trenail seats into its chamfered recess, at the business end of a big hammer. Trenails are always wedged inside the boat, as I described, or should be.
As far as your comment about "...working too hard.", I can only say that it is very often the case in this boat business that excellence costs time and effort. Cheaper, easier methods that are "...just as good..." are very, very seldom things, and so it is in this case as well. At least on normal carvel planking, it is best to spend the extra effort and do it right. The results will prove that, eventually.

Jeff Lane

ROWE BOATS
03-11-2001, 05:19 PM
In my experience you don't use the trunnel to force the plank against the frame, rather to hold it there. What do you do in instances where you want to blind wedge? I also believe that the trunnel need to fit tightly enough that you wouldn't need any monkey dung under a countersunk head to keep the water out.

ROWE BOATS
03-11-2001, 05:19 PM
In my experience you don't use the trunnel to force the plank against the frame, rather to hold it there. What do you do in instances where you want to blind wedge? I also believe that the trunnel need to fit tightly enough that you wouldn't need any monkey dung under a countersunk head to keep the water out.

ROWE BOATS
03-11-2001, 05:19 PM
In my experience you don't use the trunnel to force the plank against the frame, rather to hold it there. What do you do in instances where you want to blind wedge? I also believe that the trunnel need to fit tightly enough that you wouldn't need any monkey dung under a countersunk head to keep the water out.

Ian McColgin
03-11-2001, 05:44 PM
Maybe we only think we know what we've tried. I'd done some blind wedge fitting in furniture and always thought it might have an applications on boats, but have not done it myself because, as RoweBoats points out, the fit is really tight.

I'd only seen straight trennels in both traditional construction and epoxy applications, so I just kept with it.

I don't really know how much shear stress can be found between the frames and planks, but I do know that the diameter of fastenings gets dramaticly smaller in metal fastenings than for trennels in a similar boat. My impression of wood is that shear strength increases with diameter more dramaticly than resistance to pulling. From that impression I reasoned that a trennel that looked like a nail or screw would be a matter of maximizing wood's vices without gaining wood's virtues. Also, the trennels of that shape for sail in certain august publications cost money or would be work to make, whilst the low tech straight trennel was within my ability to make fast and easy.

As I've pointed out before, I let the trennel hold the wood in place but the trennel is not what brings it into place. That's done by clamps, wedges from outside, and in rare instances bolts. Same is really true of metal fastenings if they are nails. The plank must be home and sitting hard on the frame before you pound away. Same really with screws or you risk stripping the hole.

Rowe is of course right that the fit should be tight enough that you don't need a glue. I like a bit of thin epoxy since that's what was done with such success on Grana before me and because the epoxy acts as a lubricant when setting the trennel.

At any rate, we've somre real pros out there who can perhaps inform us as to how much pull power matters and how much shear strength, regardless of the type of fastening.

Ian McColgin
03-11-2001, 05:44 PM
Maybe we only think we know what we've tried. I'd done some blind wedge fitting in furniture and always thought it might have an applications on boats, but have not done it myself because, as RoweBoats points out, the fit is really tight.

I'd only seen straight trennels in both traditional construction and epoxy applications, so I just kept with it.

I don't really know how much shear stress can be found between the frames and planks, but I do know that the diameter of fastenings gets dramaticly smaller in metal fastenings than for trennels in a similar boat. My impression of wood is that shear strength increases with diameter more dramaticly than resistance to pulling. From that impression I reasoned that a trennel that looked like a nail or screw would be a matter of maximizing wood's vices without gaining wood's virtues. Also, the trennels of that shape for sail in certain august publications cost money or would be work to make, whilst the low tech straight trennel was within my ability to make fast and easy.

As I've pointed out before, I let the trennel hold the wood in place but the trennel is not what brings it into place. That's done by clamps, wedges from outside, and in rare instances bolts. Same is really true of metal fastenings if they are nails. The plank must be home and sitting hard on the frame before you pound away. Same really with screws or you risk stripping the hole.

Rowe is of course right that the fit should be tight enough that you don't need a glue. I like a bit of thin epoxy since that's what was done with such success on Grana before me and because the epoxy acts as a lubricant when setting the trennel.

At any rate, we've somre real pros out there who can perhaps inform us as to how much pull power matters and how much shear strength, regardless of the type of fastening.

Ian McColgin
03-11-2001, 05:44 PM
Maybe we only think we know what we've tried. I'd done some blind wedge fitting in furniture and always thought it might have an applications on boats, but have not done it myself because, as RoweBoats points out, the fit is really tight.

I'd only seen straight trennels in both traditional construction and epoxy applications, so I just kept with it.

I don't really know how much shear stress can be found between the frames and planks, but I do know that the diameter of fastenings gets dramaticly smaller in metal fastenings than for trennels in a similar boat. My impression of wood is that shear strength increases with diameter more dramaticly than resistance to pulling. From that impression I reasoned that a trennel that looked like a nail or screw would be a matter of maximizing wood's vices without gaining wood's virtues. Also, the trennels of that shape for sail in certain august publications cost money or would be work to make, whilst the low tech straight trennel was within my ability to make fast and easy.

As I've pointed out before, I let the trennel hold the wood in place but the trennel is not what brings it into place. That's done by clamps, wedges from outside, and in rare instances bolts. Same is really true of metal fastenings if they are nails. The plank must be home and sitting hard on the frame before you pound away. Same really with screws or you risk stripping the hole.

Rowe is of course right that the fit should be tight enough that you don't need a glue. I like a bit of thin epoxy since that's what was done with such success on Grana before me and because the epoxy acts as a lubricant when setting the trennel.

At any rate, we've somre real pros out there who can perhaps inform us as to how much pull power matters and how much shear strength, regardless of the type of fastening.

Jeff Lane
03-11-2001, 07:50 PM
For Rowe Boats, and also Ian McColgin:

1. Yes, the planks should be clamped well to the frames before fastening them. That doesn't change the fact that a positive inward force holding them there, provided by a driven, headed trenail, gives a superior holding effect both when installing them, and when the vessel is being mauled by heavy, or even not-so-heavy seas. Non-headed, unglued trenails sometimes tend to allow the planks to spring out, as shown by the trenail outer ends "sinking" into their holes in the planking, while I have very seldom seen proper, headed ones do that.
Glued trenails are impossible to knock out for planking repairs, and most trenails aren't installed blind (unless for some reason that is particularly necessary), because one can't control the wedge thickness effective in the trenail that way quite as well as when it is open and visible, and because the fit of the head is better felt when no blind wedge is present. You can still use headed trenails with blind wedges, but it is trickier, and requires a better feel for the situation when hammering the trenail in.
Sometimes, in some rare instances, I've had to use them, but not often.
It seems obvious that the inward-holding power of headed trenails is superior to a fastener that provides no inward force at all, and has no head for the plank to push itself over. (Yes, I know about the wedges you put in on the outside. I use them myself on headed trenails as well.)

2. About sealing the heads with and without sealant, if you use hard trenails in soft planking, or even soft trenails in soft planking, you most likely don't need sealant. When you use hard trenails in hard planking, as I sometimes do, it is not quite as easy to get a perfect fit, as the two parts of the system must be very exactly machined to mate perfectly to do that. If you have hand-cut the chamfer in the planking hole, you may very likely need sealant. If you have machined it, that is less likely, but is a good insurance for a well-sealed hole. Here we are talking about greenheart trenails in oak planking, and the like.
I look at that part as good insurance, especially if you hit the trenail just once too many times, and tiny splits develop in the diameter of the planking hole. The goo will seal it anyway, and it will be much less likely to rot through fresh water intrusion.

3. The raw linseed oil/Cuprinol mixture I use is good lubrication, and is rot-preventative as well.

4. I don't quite understand your reference to "shear strength", Ian. as the plank-to-trenail shear strength of headed and straight trenails is almost exactly the same, their diameters being equal except for the tiny added area of the flared head. If you mean the
shearing forces developed within the trenail itself around the circumference of the head, caused by the plank trying to pull off over either the flared, wedged head of a headed trenail, or the wedged flare only of a straight one, those forces, too, would be very nearly the same, because the lengths of the circumference are just about the same. I guess I don't understand what you are saying, please explain.

5. Yes, trenails are of much greater diameter than metal fastenings. That is because the trenail is basically a much weaker fastening, for its size, being made of wood and not of metal. A fairly large trenail doesn't have nearly the shear strength of even a fairly small metal fastener, but there are many kinds of strengths...the trenail will never corrode the wood of the plank or frame, or, if properly done, rot either itself or the wood around it.
Also, it frequently isn't the shear strength of the fastener, but its bearing area on the wood around it, that decides a fastener's ability to withstand heavy shear loadings between plank and frame.

6. Because a headed trenail gives a good push on the plank to hold that plank onto the frame, it acts, in that way, like a headed metal screw. That is not a bad thing, but a very good one.
Because a non-headed trenail does not do this, it does not act like a headed metal screw, and that is not a good thing, but a very bad one, if what you intended to do was to hold the plank on.
(That, by the way, is what I intended to do all along.)
I'm not sure what else to say about "...wood's virtues" or "vices". I can say, though, that a trenail, because of its
much greater diameter, provides a much lower bearing load on the wood it is in, when subjected to shearing loads induced by either wind and wave loadings, or by vertical planking growth through water absorption. (If the swelling of the planking is great enough, the trenail can be sheared right off, but then a metal fastener wouldn't be very effective in that circumstance either.)
Anyway, the discussion isn't about metal vs. wood, but headed vs. straight trenails.

7. The fact that manufactured trenails have heads at all may give you some indication as to their desireability. No one has said that quality isn't expensive, or that it is easy, Ian.
I do feel that quality is desireable, though. As a staunch adherant to the thinking behind both Murphy's Law and O'Brien's corollary, I try to make what I do as resistant to failure as I can, knowing that with that attitude, I may have a fair chance of success, while without it there is little chance of success, either sooner or later. And, by the way, if anyone asks you how much pulling power matters, and how much sheer strength matters, please tell them for me that both matter a whole lot, as those strengths are what hold the planking on, and both are about equally important. A sprung plank can ruin your whole afternoon; I've seen that happen.

Cheers, Jeff Lane

Jeff Lane
03-11-2001, 07:50 PM
For Rowe Boats, and also Ian McColgin:

1. Yes, the planks should be clamped well to the frames before fastening them. That doesn't change the fact that a positive inward force holding them there, provided by a driven, headed trenail, gives a superior holding effect both when installing them, and when the vessel is being mauled by heavy, or even not-so-heavy seas. Non-headed, unglued trenails sometimes tend to allow the planks to spring out, as shown by the trenail outer ends "sinking" into their holes in the planking, while I have very seldom seen proper, headed ones do that.
Glued trenails are impossible to knock out for planking repairs, and most trenails aren't installed blind (unless for some reason that is particularly necessary), because one can't control the wedge thickness effective in the trenail that way quite as well as when it is open and visible, and because the fit of the head is better felt when no blind wedge is present. You can still use headed trenails with blind wedges, but it is trickier, and requires a better feel for the situation when hammering the trenail in.
Sometimes, in some rare instances, I've had to use them, but not often.
It seems obvious that the inward-holding power of headed trenails is superior to a fastener that provides no inward force at all, and has no head for the plank to push itself over. (Yes, I know about the wedges you put in on the outside. I use them myself on headed trenails as well.)

2. About sealing the heads with and without sealant, if you use hard trenails in soft planking, or even soft trenails in soft planking, you most likely don't need sealant. When you use hard trenails in hard planking, as I sometimes do, it is not quite as easy to get a perfect fit, as the two parts of the system must be very exactly machined to mate perfectly to do that. If you have hand-cut the chamfer in the planking hole, you may very likely need sealant. If you have machined it, that is less likely, but is a good insurance for a well-sealed hole. Here we are talking about greenheart trenails in oak planking, and the like.
I look at that part as good insurance, especially if you hit the trenail just once too many times, and tiny splits develop in the diameter of the planking hole. The goo will seal it anyway, and it will be much less likely to rot through fresh water intrusion.

3. The raw linseed oil/Cuprinol mixture I use is good lubrication, and is rot-preventative as well.

4. I don't quite understand your reference to "shear strength", Ian. as the plank-to-trenail shear strength of headed and straight trenails is almost exactly the same, their diameters being equal except for the tiny added area of the flared head. If you mean the
shearing forces developed within the trenail itself around the circumference of the head, caused by the plank trying to pull off over either the flared, wedged head of a headed trenail, or the wedged flare only of a straight one, those forces, too, would be very nearly the same, because the lengths of the circumference are just about the same. I guess I don't understand what you are saying, please explain.

5. Yes, trenails are of much greater diameter than metal fastenings. That is because the trenail is basically a much weaker fastening, for its size, being made of wood and not of metal. A fairly large trenail doesn't have nearly the shear strength of even a fairly small metal fastener, but there are many kinds of strengths...the trenail will never corrode the wood of the plank or frame, or, if properly done, rot either itself or the wood around it.
Also, it frequently isn't the shear strength of the fastener, but its bearing area on the wood around it, that decides a fastener's ability to withstand heavy shear loadings between plank and frame.

6. Because a headed trenail gives a good push on the plank to hold that plank onto the frame, it acts, in that way, like a headed metal screw. That is not a bad thing, but a very good one.
Because a non-headed trenail does not do this, it does not act like a headed metal screw, and that is not a good thing, but a very bad one, if what you intended to do was to hold the plank on.
(That, by the way, is what I intended to do all along.)
I'm not sure what else to say about "...wood's virtues" or "vices". I can say, though, that a trenail, because of its
much greater diameter, provides a much lower bearing load on the wood it is in, when subjected to shearing loads induced by either wind and wave loadings, or by vertical planking growth through water absorption. (If the swelling of the planking is great enough, the trenail can be sheared right off, but then a metal fastener wouldn't be very effective in that circumstance either.)
Anyway, the discussion isn't about metal vs. wood, but headed vs. straight trenails.

7. The fact that manufactured trenails have heads at all may give you some indication as to their desireability. No one has said that quality isn't expensive, or that it is easy, Ian.
I do feel that quality is desireable, though. As a staunch adherant to the thinking behind both Murphy's Law and O'Brien's corollary, I try to make what I do as resistant to failure as I can, knowing that with that attitude, I may have a fair chance of success, while without it there is little chance of success, either sooner or later. And, by the way, if anyone asks you how much pulling power matters, and how much sheer strength matters, please tell them for me that both matter a whole lot, as those strengths are what hold the planking on, and both are about equally important. A sprung plank can ruin your whole afternoon; I've seen that happen.

Cheers, Jeff Lane

Jeff Lane
03-11-2001, 07:50 PM
For Rowe Boats, and also Ian McColgin:

1. Yes, the planks should be clamped well to the frames before fastening them. That doesn't change the fact that a positive inward force holding them there, provided by a driven, headed trenail, gives a superior holding effect both when installing them, and when the vessel is being mauled by heavy, or even not-so-heavy seas. Non-headed, unglued trenails sometimes tend to allow the planks to spring out, as shown by the trenail outer ends "sinking" into their holes in the planking, while I have very seldom seen proper, headed ones do that.
Glued trenails are impossible to knock out for planking repairs, and most trenails aren't installed blind (unless for some reason that is particularly necessary), because one can't control the wedge thickness effective in the trenail that way quite as well as when it is open and visible, and because the fit of the head is better felt when no blind wedge is present. You can still use headed trenails with blind wedges, but it is trickier, and requires a better feel for the situation when hammering the trenail in.
Sometimes, in some rare instances, I've had to use them, but not often.
It seems obvious that the inward-holding power of headed trenails is superior to a fastener that provides no inward force at all, and has no head for the plank to push itself over. (Yes, I know about the wedges you put in on the outside. I use them myself on headed trenails as well.)

2. About sealing the heads with and without sealant, if you use hard trenails in soft planking, or even soft trenails in soft planking, you most likely don't need sealant. When you use hard trenails in hard planking, as I sometimes do, it is not quite as easy to get a perfect fit, as the two parts of the system must be very exactly machined to mate perfectly to do that. If you have hand-cut the chamfer in the planking hole, you may very likely need sealant. If you have machined it, that is less likely, but is a good insurance for a well-sealed hole. Here we are talking about greenheart trenails in oak planking, and the like.
I look at that part as good insurance, especially if you hit the trenail just once too many times, and tiny splits develop in the diameter of the planking hole. The goo will seal it anyway, and it will be much less likely to rot through fresh water intrusion.

3. The raw linseed oil/Cuprinol mixture I use is good lubrication, and is rot-preventative as well.

4. I don't quite understand your reference to "shear strength", Ian. as the plank-to-trenail shear strength of headed and straight trenails is almost exactly the same, their diameters being equal except for the tiny added area of the flared head. If you mean the
shearing forces developed within the trenail itself around the circumference of the head, caused by the plank trying to pull off over either the flared, wedged head of a headed trenail, or the wedged flare only of a straight one, those forces, too, would be very nearly the same, because the lengths of the circumference are just about the same. I guess I don't understand what you are saying, please explain.

5. Yes, trenails are of much greater diameter than metal fastenings. That is because the trenail is basically a much weaker fastening, for its size, being made of wood and not of metal. A fairly large trenail doesn't have nearly the shear strength of even a fairly small metal fastener, but there are many kinds of strengths...the trenail will never corrode the wood of the plank or frame, or, if properly done, rot either itself or the wood around it.
Also, it frequently isn't the shear strength of the fastener, but its bearing area on the wood around it, that decides a fastener's ability to withstand heavy shear loadings between plank and frame.

6. Because a headed trenail gives a good push on the plank to hold that plank onto the frame, it acts, in that way, like a headed metal screw. That is not a bad thing, but a very good one.
Because a non-headed trenail does not do this, it does not act like a headed metal screw, and that is not a good thing, but a very bad one, if what you intended to do was to hold the plank on.
(That, by the way, is what I intended to do all along.)
I'm not sure what else to say about "...wood's virtues" or "vices". I can say, though, that a trenail, because of its
much greater diameter, provides a much lower bearing load on the wood it is in, when subjected to shearing loads induced by either wind and wave loadings, or by vertical planking growth through water absorption. (If the swelling of the planking is great enough, the trenail can be sheared right off, but then a metal fastener wouldn't be very effective in that circumstance either.)
Anyway, the discussion isn't about metal vs. wood, but headed vs. straight trenails.

7. The fact that manufactured trenails have heads at all may give you some indication as to their desireability. No one has said that quality isn't expensive, or that it is easy, Ian.
I do feel that quality is desireable, though. As a staunch adherant to the thinking behind both Murphy's Law and O'Brien's corollary, I try to make what I do as resistant to failure as I can, knowing that with that attitude, I may have a fair chance of success, while without it there is little chance of success, either sooner or later. And, by the way, if anyone asks you how much pulling power matters, and how much sheer strength matters, please tell them for me that both matter a whole lot, as those strengths are what hold the planking on, and both are about equally important. A sprung plank can ruin your whole afternoon; I've seen that happen.

Cheers, Jeff Lane

Thad
03-12-2001, 06:29 AM
Good stuff Jeff! I appreciate seeing it.

Thad
03-12-2001, 06:29 AM
Good stuff Jeff! I appreciate seeing it.

Thad
03-12-2001, 06:29 AM
Good stuff Jeff! I appreciate seeing it.

Ian McColgin
03-12-2001, 09:05 AM
Thank you Jeff. The only manufactored trennels I'd seen appeared to have a rather thin 'shank.' The slightly flaired head you describe makes more sense and obviates any concern about strength.

I think, however, I'll stick to the straight trennel for the same reason that you stick to the flared trennel - I'm used to it, never had a problem, etc etc.

I really don't like wedges, blind or surface, in this application since that means a least cracking the trennel, admiting moisture etc, and may well overstress the wood around the hole.

I also think that boring a simple straight hole is an easier way to get a tight fit but, as they say, whatever floats your boat.

G'luck

Ian McColgin
03-12-2001, 09:05 AM
Thank you Jeff. The only manufactored trennels I'd seen appeared to have a rather thin 'shank.' The slightly flaired head you describe makes more sense and obviates any concern about strength.

I think, however, I'll stick to the straight trennel for the same reason that you stick to the flared trennel - I'm used to it, never had a problem, etc etc.

I really don't like wedges, blind or surface, in this application since that means a least cracking the trennel, admiting moisture etc, and may well overstress the wood around the hole.

I also think that boring a simple straight hole is an easier way to get a tight fit but, as they say, whatever floats your boat.

G'luck

Ian McColgin
03-12-2001, 09:05 AM
Thank you Jeff. The only manufactored trennels I'd seen appeared to have a rather thin 'shank.' The slightly flaired head you describe makes more sense and obviates any concern about strength.

I think, however, I'll stick to the straight trennel for the same reason that you stick to the flared trennel - I'm used to it, never had a problem, etc etc.

I really don't like wedges, blind or surface, in this application since that means a least cracking the trennel, admiting moisture etc, and may well overstress the wood around the hole.

I also think that boring a simple straight hole is an easier way to get a tight fit but, as they say, whatever floats your boat.

G'luck

ROWE BOATS
03-13-2001, 04:54 PM
I don't object to the use of headed trunnels, I just don't think they are necessary if properly installed and wedged. When you turn trunnels on a trunnel lathe with a hollow auger they have a chamferred end where you stop the auger short of the headstock. I don't consider this a headed trunnel, but I guess you could use it as such. Couldn't hurt. As to the planking standing proud of the trunnel, I believe this is not a result of the planking springing from the frames but is a result of the different rate of swelling in the grain of the planking and the long grain of the trunnel which hardly swells at all.

ROWE BOATS
03-13-2001, 04:54 PM
I don't object to the use of headed trunnels, I just don't think they are necessary if properly installed and wedged. When you turn trunnels on a trunnel lathe with a hollow auger they have a chamferred end where you stop the auger short of the headstock. I don't consider this a headed trunnel, but I guess you could use it as such. Couldn't hurt. As to the planking standing proud of the trunnel, I believe this is not a result of the planking springing from the frames but is a result of the different rate of swelling in the grain of the planking and the long grain of the trunnel which hardly swells at all.

ROWE BOATS
03-13-2001, 04:54 PM
I don't object to the use of headed trunnels, I just don't think they are necessary if properly installed and wedged. When you turn trunnels on a trunnel lathe with a hollow auger they have a chamferred end where you stop the auger short of the headstock. I don't consider this a headed trunnel, but I guess you could use it as such. Couldn't hurt. As to the planking standing proud of the trunnel, I believe this is not a result of the planking springing from the frames but is a result of the different rate of swelling in the grain of the planking and the long grain of the trunnel which hardly swells at all.

Jeff Lane
03-14-2001, 02:23 AM
Mr. Rowe, with all due respect:

I began learning about trenails in 1963, when my wife, son and I came to Norway and bought the vessel I still own, and renewed the forward third of her. Because I wanted to restore the boat, and not just repair her, (as Gladhval has since then represented just about my only capital, and eventually I must either sink or sell her), I tried to learn as much,and, of necessity as quickly as I could about her construction. I found that, from the standpoint of my engineering background, her
original construction left much to be desired. It appeared to me that the builders had, in several cases, learned over a very long experience of building to "improve" previous faults or failures of construction by making things heavier, and not necessarily better fastened
and/or joined together. In this way, they did gain at least some increased structural performance, but at great cost of materials and weight. I therefore tried to improve both the connections between her various structural components, and the quality of those components, as far as our scant resources would allow, in an effort to make what I was building last better. (Here I must say that the "old people" didn't do all that badly; She was then 44 years old, and would have been in better shape but for the onslaught of a tree-dwelling insect).

At any rate, the one thing I could not see any reason to change either the method or materials of were her juniper trenails, which had proven to be the saving of the vessel for us. As juniper would have cost more than we could possibly have afforded, other materials and methods were necessary, and I have spent a good part of the time since then trying other methods, among them yours.

Because her planking is 2" oak, and we renewed it in oak, it was necessary to find materials that would have the necessary strength and longevity to hold the hard planking, while being affordable, and to use trenail shapes that would help perhaps softer trenail woods to do the job anyway.

I found that the original shape of the headed trenail, as used on both Gladhval and nearly every other Norwegian boat I have dealt with since, and as described at the beginning of this thread, whether arrived at through using hardwood with or without outside wedges, or Norwegian pine with outside wedges, is superior in holding power and longevity to other shapes, including the straight, wedged trenails that you prefer.

That is why I use that shape to this day, on both my own boat and the many others I have to do with. I decided early on to keep methods that were either too
good or too costly to improve
upon; Had I not done so we never would have gone anywhere. Although I cannot afford to be what one would describe as a " serious cruising person", I have sailed that boat somewhere around 25,000 sea miles since then, some of them hard ones. I have sailed her nine times across the North Sea, twice across the Atlantic, and helped her batter her way around several of the worst coasts in the world. While what you say about the dimensional difference between longitudinal and lateral expansion (trenail vs plank expansion) is certainly true, please believe me when I say I can tell the difference between that and a plank standing slightly off a frame, after a 45-ton vessel has been dropped several meters off a wave into a trough.

I gave the method that started this thread because it seemed clear that many needed to hear it, in order to avoid the several years of trial-and-error that would, if they persisted, most likely bring them to the same conclusions that I arrived at, now so many years ago. In this case, I must say that quite a lot more than a thousand years of using trenails has taught the Norwegian boatbuilders the best ways to do that, and if some of their other, younger methods of construction show deficiencies, at least that particular side does not.

I've said it the way experience has taught me is best, and it doesn't matter to me if you prefer other methods. I would suggest, though, that you try both methods on a test vessel, take it out and hammer it in very rough seas for a few years, and then decide by looking at the results, as I have done, which method to continue with.

Thanks for your comments, and your opinions. As Ian McColgin put it, "...whatever floats your boat."

Most Sincerely, Jeff Lane

Jeff Lane
03-14-2001, 02:23 AM
Mr. Rowe, with all due respect:

I began learning about trenails in 1963, when my wife, son and I came to Norway and bought the vessel I still own, and renewed the forward third of her. Because I wanted to restore the boat, and not just repair her, (as Gladhval has since then represented just about my only capital, and eventually I must either sink or sell her), I tried to learn as much,and, of necessity as quickly as I could about her construction. I found that, from the standpoint of my engineering background, her
original construction left much to be desired. It appeared to me that the builders had, in several cases, learned over a very long experience of building to "improve" previous faults or failures of construction by making things heavier, and not necessarily better fastened
and/or joined together. In this way, they did gain at least some increased structural performance, but at great cost of materials and weight. I therefore tried to improve both the connections between her various structural components, and the quality of those components, as far as our scant resources would allow, in an effort to make what I was building last better. (Here I must say that the "old people" didn't do all that badly; She was then 44 years old, and would have been in better shape but for the onslaught of a tree-dwelling insect).

At any rate, the one thing I could not see any reason to change either the method or materials of were her juniper trenails, which had proven to be the saving of the vessel for us. As juniper would have cost more than we could possibly have afforded, other materials and methods were necessary, and I have spent a good part of the time since then trying other methods, among them yours.

Because her planking is 2" oak, and we renewed it in oak, it was necessary to find materials that would have the necessary strength and longevity to hold the hard planking, while being affordable, and to use trenail shapes that would help perhaps softer trenail woods to do the job anyway.

I found that the original shape of the headed trenail, as used on both Gladhval and nearly every other Norwegian boat I have dealt with since, and as described at the beginning of this thread, whether arrived at through using hardwood with or without outside wedges, or Norwegian pine with outside wedges, is superior in holding power and longevity to other shapes, including the straight, wedged trenails that you prefer.

That is why I use that shape to this day, on both my own boat and the many others I have to do with. I decided early on to keep methods that were either too
good or too costly to improve
upon; Had I not done so we never would have gone anywhere. Although I cannot afford to be what one would describe as a " serious cruising person", I have sailed that boat somewhere around 25,000 sea miles since then, some of them hard ones. I have sailed her nine times across the North Sea, twice across the Atlantic, and helped her batter her way around several of the worst coasts in the world. While what you say about the dimensional difference between longitudinal and lateral expansion (trenail vs plank expansion) is certainly true, please believe me when I say I can tell the difference between that and a plank standing slightly off a frame, after a 45-ton vessel has been dropped several meters off a wave into a trough.

I gave the method that started this thread because it seemed clear that many needed to hear it, in order to avoid the several years of trial-and-error that would, if they persisted, most likely bring them to the same conclusions that I arrived at, now so many years ago. In this case, I must say that quite a lot more than a thousand years of using trenails has taught the Norwegian boatbuilders the best ways to do that, and if some of their other, younger methods of construction show deficiencies, at least that particular side does not.

I've said it the way experience has taught me is best, and it doesn't matter to me if you prefer other methods. I would suggest, though, that you try both methods on a test vessel, take it out and hammer it in very rough seas for a few years, and then decide by looking at the results, as I have done, which method to continue with.

Thanks for your comments, and your opinions. As Ian McColgin put it, "...whatever floats your boat."

Most Sincerely, Jeff Lane

Jeff Lane
03-14-2001, 02:23 AM
Mr. Rowe, with all due respect:

I began learning about trenails in 1963, when my wife, son and I came to Norway and bought the vessel I still own, and renewed the forward third of her. Because I wanted to restore the boat, and not just repair her, (as Gladhval has since then represented just about my only capital, and eventually I must either sink or sell her), I tried to learn as much,and, of necessity as quickly as I could about her construction. I found that, from the standpoint of my engineering background, her
original construction left much to be desired. It appeared to me that the builders had, in several cases, learned over a very long experience of building to "improve" previous faults or failures of construction by making things heavier, and not necessarily better fastened
and/or joined together. In this way, they did gain at least some increased structural performance, but at great cost of materials and weight. I therefore tried to improve both the connections between her various structural components, and the quality of those components, as far as our scant resources would allow, in an effort to make what I was building last better. (Here I must say that the "old people" didn't do all that badly; She was then 44 years old, and would have been in better shape but for the onslaught of a tree-dwelling insect).

At any rate, the one thing I could not see any reason to change either the method or materials of were her juniper trenails, which had proven to be the saving of the vessel for us. As juniper would have cost more than we could possibly have afforded, other materials and methods were necessary, and I have spent a good part of the time since then trying other methods, among them yours.

Because her planking is 2" oak, and we renewed it in oak, it was necessary to find materials that would have the necessary strength and longevity to hold the hard planking, while being affordable, and to use trenail shapes that would help perhaps softer trenail woods to do the job anyway.

I found that the original shape of the headed trenail, as used on both Gladhval and nearly every other Norwegian boat I have dealt with since, and as described at the beginning of this thread, whether arrived at through using hardwood with or without outside wedges, or Norwegian pine with outside wedges, is superior in holding power and longevity to other shapes, including the straight, wedged trenails that you prefer.

That is why I use that shape to this day, on both my own boat and the many others I have to do with. I decided early on to keep methods that were either too
good or too costly to improve
upon; Had I not done so we never would have gone anywhere. Although I cannot afford to be what one would describe as a " serious cruising person", I have sailed that boat somewhere around 25,000 sea miles since then, some of them hard ones. I have sailed her nine times across the North Sea, twice across the Atlantic, and helped her batter her way around several of the worst coasts in the world. While what you say about the dimensional difference between longitudinal and lateral expansion (trenail vs plank expansion) is certainly true, please believe me when I say I can tell the difference between that and a plank standing slightly off a frame, after a 45-ton vessel has been dropped several meters off a wave into a trough.

I gave the method that started this thread because it seemed clear that many needed to hear it, in order to avoid the several years of trial-and-error that would, if they persisted, most likely bring them to the same conclusions that I arrived at, now so many years ago. In this case, I must say that quite a lot more than a thousand years of using trenails has taught the Norwegian boatbuilders the best ways to do that, and if some of their other, younger methods of construction show deficiencies, at least that particular side does not.

I've said it the way experience has taught me is best, and it doesn't matter to me if you prefer other methods. I would suggest, though, that you try both methods on a test vessel, take it out and hammer it in very rough seas for a few years, and then decide by looking at the results, as I have done, which method to continue with.

Thanks for your comments, and your opinions. As Ian McColgin put it, "...whatever floats your boat."

Most Sincerely, Jeff Lane

ROWE BOATS
03-17-2001, 07:02 AM
For Jeff Lane, From the tone of your last thread it seems that I may have offended you. If so, I apologize. I was just giving my opinion based on my experience. I had no idea that you had spent near forty years studying trunnels, and I bow to your expertise. If I ever need to know anything else about a trunnel, by God you're the man I'll ask.

ROWE BOATS
03-17-2001, 07:02 AM
For Jeff Lane, From the tone of your last thread it seems that I may have offended you. If so, I apologize. I was just giving my opinion based on my experience. I had no idea that you had spent near forty years studying trunnels, and I bow to your expertise. If I ever need to know anything else about a trunnel, by God you're the man I'll ask.

ROWE BOATS
03-17-2001, 07:02 AM
For Jeff Lane, From the tone of your last thread it seems that I may have offended you. If so, I apologize. I was just giving my opinion based on my experience. I had no idea that you had spent near forty years studying trunnels, and I bow to your expertise. If I ever need to know anything else about a trunnel, by God you're the man I'll ask.

Jeff Lane
03-17-2001, 07:42 PM
Mr. Rowe, I certainly do realize that no offense was intended, and there was none taken. If my comments struck you as testy, I apologize, as that was not my intention. I really do appreciate your comments, and all of the others, too. I feel that if we can learn to just use our brains to think of how what we are doing will turn out, as many sides of the situation at hand as we can manage to imagine BEFORE we go through the trial-and-error part, our efforts will be a good bit less trouble-ridden, and discussions like this one can help all of us to do that.

In that event, whatever any of us say that helps or forces people to think, and to evaluate various systems and methods as well as they can before they just "do something" for no very good reason (and thereby mess up), those words are much cheaper to use than the real time and materials that others are paying for. If that process helps people to make the right decisions beforehand, then it is a really worthwhile effort to say them.

Boating and boatbuilding have a penchant for bringing out an almost religious fervor in many of us. In my experience, no other practical field of endeavor (admittedly, I haven't tried them all) brings out in many people, myself not least, such a strong urge to impress our views upon others. Very early on I learned to listen to everyone else as intently as possible, evaluate the person doing the talking, and their experience, as objectively as I could, and then try and use as much common sense as I could manage to take the course that seemed best, with the information available. I hope that our discussions provide a background that helps readers to follow that procedure. If that happens, then the time is well spent.

I look forward to discussing other facets of boating and boatbuilding with you and the other posters as soon as a topic comes up to which I can add something I feel to be positive.

Jeff Lane


.



[This message has been edited by Jeff Lane (edited 03-17-2001).]

Jeff Lane
03-17-2001, 07:42 PM
Mr. Rowe, I certainly do realize that no offense was intended, and there was none taken. If my comments struck you as testy, I apologize, as that was not my intention. I really do appreciate your comments, and all of the others, too. I feel that if we can learn to just use our brains to think of how what we are doing will turn out, as many sides of the situation at hand as we can manage to imagine BEFORE we go through the trial-and-error part, our efforts will be a good bit less trouble-ridden, and discussions like this one can help all of us to do that.

In that event, whatever any of us say that helps or forces people to think, and to evaluate various systems and methods as well as they can before they just "do something" for no very good reason (and thereby mess up), those words are much cheaper to use than the real time and materials that others are paying for. If that process helps people to make the right decisions beforehand, then it is a really worthwhile effort to say them.

Boating and boatbuilding have a penchant for bringing out an almost religious fervor in many of us. In my experience, no other practical field of endeavor (admittedly, I haven't tried them all) brings out in many people, myself not least, such a strong urge to impress our views upon others. Very early on I learned to listen to everyone else as intently as possible, evaluate the person doing the talking, and their experience, as objectively as I could, and then try and use as much common sense as I could manage to take the course that seemed best, with the information available. I hope that our discussions provide a background that helps readers to follow that procedure. If that happens, then the time is well spent.

I look forward to discussing other facets of boating and boatbuilding with you and the other posters as soon as a topic comes up to which I can add something I feel to be positive.

Jeff Lane


.



[This message has been edited by Jeff Lane (edited 03-17-2001).]

Jeff Lane
03-17-2001, 07:42 PM
Mr. Rowe, I certainly do realize that no offense was intended, and there was none taken. If my comments struck you as testy, I apologize, as that was not my intention. I really do appreciate your comments, and all of the others, too. I feel that if we can learn to just use our brains to think of how what we are doing will turn out, as many sides of the situation at hand as we can manage to imagine BEFORE we go through the trial-and-error part, our efforts will be a good bit less trouble-ridden, and discussions like this one can help all of us to do that.

In that event, whatever any of us say that helps or forces people to think, and to evaluate various systems and methods as well as they can before they just "do something" for no very good reason (and thereby mess up), those words are much cheaper to use than the real time and materials that others are paying for. If that process helps people to make the right decisions beforehand, then it is a really worthwhile effort to say them.

Boating and boatbuilding have a penchant for bringing out an almost religious fervor in many of us. In my experience, no other practical field of endeavor (admittedly, I haven't tried them all) brings out in many people, myself not least, such a strong urge to impress our views upon others. Very early on I learned to listen to everyone else as intently as possible, evaluate the person doing the talking, and their experience, as objectively as I could, and then try and use as much common sense as I could manage to take the course that seemed best, with the information available. I hope that our discussions provide a background that helps readers to follow that procedure. If that happens, then the time is well spent.

I look forward to discussing other facets of boating and boatbuilding with you and the other posters as soon as a topic comes up to which I can add something I feel to be positive.

Jeff Lane


.



[This message has been edited by Jeff Lane (edited 03-17-2001).]

Peter Sibley
03-28-2001, 05:31 PM
Gentlemen,
there is obviously a wealth of knowlege floating about amongst the various posters ,so a question if I may.What dimension hardwood trunnels [headed Mr Lane],would you use in hardwood sawn frames 2" sided,[ie doubled =4"]x3 1/2".Planking thickness 1 1/8" also hardwood .I'm in Australia and we have some excellent hardwood.Thanks for any advice.

Peter Sibley
03-28-2001, 05:31 PM
Gentlemen,
there is obviously a wealth of knowlege floating about amongst the various posters ,so a question if I may.What dimension hardwood trunnels [headed Mr Lane],would you use in hardwood sawn frames 2" sided,[ie doubled =4"]x3 1/2".Planking thickness 1 1/8" also hardwood .I'm in Australia and we have some excellent hardwood.Thanks for any advice.

Peter Sibley
03-28-2001, 05:31 PM
Gentlemen,
there is obviously a wealth of knowlege floating about amongst the various posters ,so a question if I may.What dimension hardwood trunnels [headed Mr Lane],would you use in hardwood sawn frames 2" sided,[ie doubled =4"]x3 1/2".Planking thickness 1 1/8" also hardwood .I'm in Australia and we have some excellent hardwood.Thanks for any advice.

Jeff Lane
03-29-2001, 02:29 AM
Mr. Sibley, that is a tricky question. Although I don't know the woods you are using, I am of the opinion that 2" sided frames are most likely right on the edge of as thin as you can still use trenails with, or over that edge, because of the danger of splitting the frame when wedging on the inside.

I would suggest that you make a test double frame, and trenail at least four plank stubs to it, using both
11/16" and 3/4" diameter, headed hardwood trenails, and see how well the frame resists splitting. Be sure to
orient the inside wedge horizontally, so that it wedges vertically, against the grain of the frame.

I'd appreciate knowing how your test comes out, and which woods you are using.
I've always thought that 3" sided was about the lower safe thickness limit for trenailed frames. My address is:
<jeff.lane@hl.telia.no>

Thanks in advance,
Jeff Lane

Jeff Lane
03-29-2001, 02:29 AM
Mr. Sibley, that is a tricky question. Although I don't know the woods you are using, I am of the opinion that 2" sided frames are most likely right on the edge of as thin as you can still use trenails with, or over that edge, because of the danger of splitting the frame when wedging on the inside.

I would suggest that you make a test double frame, and trenail at least four plank stubs to it, using both
11/16" and 3/4" diameter, headed hardwood trenails, and see how well the frame resists splitting. Be sure to
orient the inside wedge horizontally, so that it wedges vertically, against the grain of the frame.

I'd appreciate knowing how your test comes out, and which woods you are using.
I've always thought that 3" sided was about the lower safe thickness limit for trenailed frames. My address is:
<jeff.lane@hl.telia.no>

Thanks in advance,
Jeff Lane

Jeff Lane
03-29-2001, 02:29 AM
Mr. Sibley, that is a tricky question. Although I don't know the woods you are using, I am of the opinion that 2" sided frames are most likely right on the edge of as thin as you can still use trenails with, or over that edge, because of the danger of splitting the frame when wedging on the inside.

I would suggest that you make a test double frame, and trenail at least four plank stubs to it, using both
11/16" and 3/4" diameter, headed hardwood trenails, and see how well the frame resists splitting. Be sure to
orient the inside wedge horizontally, so that it wedges vertically, against the grain of the frame.

I'd appreciate knowing how your test comes out, and which woods you are using.
I've always thought that 3" sided was about the lower safe thickness limit for trenailed frames. My address is:
<jeff.lane@hl.telia.no>

Thanks in advance,
Jeff Lane

Peter Sibley
04-01-2001, 04:07 AM
Mr Lane,
I'll be pleased to let you know ,it won't be for a while however,the bends I'm going to use a still in the forest,on order ,but undelivered.The species ,if you have access to a very good book on woods of the world is "Tallowood",65 lb per cubic ft,yellow ,waxy very durable and strong.Botanical name, eucalyptus microcores.

Peter Sibley
04-01-2001, 04:07 AM
Mr Lane,
I'll be pleased to let you know ,it won't be for a while however,the bends I'm going to use a still in the forest,on order ,but undelivered.The species ,if you have access to a very good book on woods of the world is "Tallowood",65 lb per cubic ft,yellow ,waxy very durable and strong.Botanical name, eucalyptus microcores.

Peter Sibley
04-01-2001, 04:07 AM
Mr Lane,
I'll be pleased to let you know ,it won't be for a while however,the bends I'm going to use a still in the forest,on order ,but undelivered.The species ,if you have access to a very good book on woods of the world is "Tallowood",65 lb per cubic ft,yellow ,waxy very durable and strong.Botanical name, eucalyptus microcores.

dadadata
04-11-2001, 10:26 AM
I'm sure trunnels of varying shapes have been used at various times. If anyone is interested in Colonial American trunnels I believe there is some discussion of some wrecks found in South Carolina in a good book called "Tidecraft" (author's first name is Rusty, can't recall the last name but it might be Fleetwood). It's a serious archaeological book.

As I recall he mentions juniper. In the USA this wood is everywhere south of the Mason Dixon line, called "red cedar" but is actually juniperus virginiana. I can't imagine it would be at all expensive to obtain quite a bit of this cedar for trunnels if anyone is inclined. I suspect the trees are available for the sawing.

Folk wisdom otherwise specifies locust, which is a weed tree hereabouts and as I understand it was used as stock by individuals who would spend the winter evenings carving trunnels by hand to sell to the local boatwrights.

I've never heard specifics on whether these were carved from branches of about the right diameter or from split bolts. I suspect they were nowhere near round anyway.

In one modern instance I know of Osage orange was used for trunnels. I don't think this was a particularly good decision (it certainly has no historical precedent) as the twisty grain causes blanks to warp, causes tear-out when planing or running into a dowel making machine, and the wood is so hard blades dull almost instantaneously. It becomes a difficult process to make the trunnels of this wood and there is lots of waste. Considering the amount of "cedar" and locust locally, it would have been simple to use either of these woods.

Based on my beach rambles, the driftwood which hangs around the longest and is the hardest is red cedar and locust. The locust in particular is as hard as concrete once you get past the outer 1/4 inch of "rust" or greyish wood... Osage driftwood is like steel, but it is far less common and falls into the "why bother?" category.

Osage, iroko and mulberry are all related. Dunno about iroko but it's possible mulberry was used for trunnels in the Chesapeake. It's common, durable, and has been documented as used for frames. Another weed tree, really.

dadadata
04-11-2001, 10:26 AM
I'm sure trunnels of varying shapes have been used at various times. If anyone is interested in Colonial American trunnels I believe there is some discussion of some wrecks found in South Carolina in a good book called "Tidecraft" (author's first name is Rusty, can't recall the last name but it might be Fleetwood). It's a serious archaeological book.

As I recall he mentions juniper. In the USA this wood is everywhere south of the Mason Dixon line, called "red cedar" but is actually juniperus virginiana. I can't imagine it would be at all expensive to obtain quite a bit of this cedar for trunnels if anyone is inclined. I suspect the trees are available for the sawing.

Folk wisdom otherwise specifies locust, which is a weed tree hereabouts and as I understand it was used as stock by individuals who would spend the winter evenings carving trunnels by hand to sell to the local boatwrights.

I've never heard specifics on whether these were carved from branches of about the right diameter or from split bolts. I suspect they were nowhere near round anyway.

In one modern instance I know of Osage orange was used for trunnels. I don't think this was a particularly good decision (it certainly has no historical precedent) as the twisty grain causes blanks to warp, causes tear-out when planing or running into a dowel making machine, and the wood is so hard blades dull almost instantaneously. It becomes a difficult process to make the trunnels of this wood and there is lots of waste. Considering the amount of "cedar" and locust locally, it would have been simple to use either of these woods.

Based on my beach rambles, the driftwood which hangs around the longest and is the hardest is red cedar and locust. The locust in particular is as hard as concrete once you get past the outer 1/4 inch of "rust" or greyish wood... Osage driftwood is like steel, but it is far less common and falls into the "why bother?" category.

Osage, iroko and mulberry are all related. Dunno about iroko but it's possible mulberry was used for trunnels in the Chesapeake. It's common, durable, and has been documented as used for frames. Another weed tree, really.

dadadata
04-11-2001, 10:26 AM
I'm sure trunnels of varying shapes have been used at various times. If anyone is interested in Colonial American trunnels I believe there is some discussion of some wrecks found in South Carolina in a good book called "Tidecraft" (author's first name is Rusty, can't recall the last name but it might be Fleetwood). It's a serious archaeological book.

As I recall he mentions juniper. In the USA this wood is everywhere south of the Mason Dixon line, called "red cedar" but is actually juniperus virginiana. I can't imagine it would be at all expensive to obtain quite a bit of this cedar for trunnels if anyone is inclined. I suspect the trees are available for the sawing.

Folk wisdom otherwise specifies locust, which is a weed tree hereabouts and as I understand it was used as stock by individuals who would spend the winter evenings carving trunnels by hand to sell to the local boatwrights.

I've never heard specifics on whether these were carved from branches of about the right diameter or from split bolts. I suspect they were nowhere near round anyway.

In one modern instance I know of Osage orange was used for trunnels. I don't think this was a particularly good decision (it certainly has no historical precedent) as the twisty grain causes blanks to warp, causes tear-out when planing or running into a dowel making machine, and the wood is so hard blades dull almost instantaneously. It becomes a difficult process to make the trunnels of this wood and there is lots of waste. Considering the amount of "cedar" and locust locally, it would have been simple to use either of these woods.

Based on my beach rambles, the driftwood which hangs around the longest and is the hardest is red cedar and locust. The locust in particular is as hard as concrete once you get past the outer 1/4 inch of "rust" or greyish wood... Osage driftwood is like steel, but it is far less common and falls into the "why bother?" category.

Osage, iroko and mulberry are all related. Dunno about iroko but it's possible mulberry was used for trunnels in the Chesapeake. It's common, durable, and has been documented as used for frames. Another weed tree, really.

Dave Fleming
04-20-2001, 04:03 PM
From an old book on Wooden Ship Building:

Treenails

Hardwood treenails are generally made from selected black locust, and may vary in diameter as driven
from 1 inches to 1 inches, depending upon the thickness of the planking. All treenails, where possible,
are driven through the ceiling inside, then cutoff flush on both ends and wedged with small oak wedges
made for that purpose and called treenail wedges. The wedges must be set across the grain of the plank
through which the treenail is driven. Where treenails are not driven through, a wedge is inserted in the end
of the treenail which, when the treenail is driven, backs up against the bottom of the hole and wedges the
treenail fast.

There are three general types of treenails in use. The first is straight, and is driven in a hole about 1/16
inch smaller than the treenail. When it is necessary to drive treenails of this type longer than 24 inches, it
becomes rather difficult to get them in with the proper amount of drift. Hence, a second type has been
devised where about one-half of the length of the treenail is sized about 1/8 inch smaller than the other
half. These are driven in holes bored first about half-way through the hull with an auger 1/16 smaller than
the large end of the treenail, and the rest of the way with an auger 1/16 smaller than the small part of the
treenail. This in effect shortens the required length of drift and makes it possible to drive much longer
treenails than would be the case with the first type. Such treenails are known as two drift treenails. The
third type is tapered and driven in a two size hole bored in the same manner as described for two drift
treenails. The large end of the treenail is about 1/8 inch larger than the larger portion of the hole, while the
small end is the same size as the smaller portion of the hole. It is claimed that these treenails, when driven
properly, cannot back out and that they actually hold the planking up against the frame.

All holes are bored, and all treenails are driven from the outside.

William Henry Curtis: The elements of Wood Ship construction ….
Philadelphia, (c1918). 23 cm, 31, 44, 45, 38, 62 pp, ill.

Published by the Education and Training Section, Industrial Relations Group, United States
Shipping Board Emergency Fleet Corporation. Part I-II copyrighted 1918, by W.H. Curtis.

Transcribed by Lars.Bruzelius@udac.se

The Maritime History Virtual Archives | Shipbuilding | Fastenings.

Copyright 1996 Lars Bruzelius. 

Dave Fleming
04-20-2001, 04:03 PM
From an old book on Wooden Ship Building:

Treenails

Hardwood treenails are generally made from selected black locust, and may vary in diameter as driven
from 1 inches to 1 inches, depending upon the thickness of the planking. All treenails, where possible,
are driven through the ceiling inside, then cutoff flush on both ends and wedged with small oak wedges
made for that purpose and called treenail wedges. The wedges must be set across the grain of the plank
through which the treenail is driven. Where treenails are not driven through, a wedge is inserted in the end
of the treenail which, when the treenail is driven, backs up against the bottom of the hole and wedges the
treenail fast.

There are three general types of treenails in use. The first is straight, and is driven in a hole about 1/16
inch smaller than the treenail. When it is necessary to drive treenails of this type longer than 24 inches, it
becomes rather difficult to get them in with the proper amount of drift. Hence, a second type has been
devised where about one-half of the length of the treenail is sized about 1/8 inch smaller than the other
half. These are driven in holes bored first about half-way through the hull with an auger 1/16 smaller than
the large end of the treenail, and the rest of the way with an auger 1/16 smaller than the small part of the
treenail. This in effect shortens the required length of drift and makes it possible to drive much longer
treenails than would be the case with the first type. Such treenails are known as two drift treenails. The
third type is tapered and driven in a two size hole bored in the same manner as described for two drift
treenails. The large end of the treenail is about 1/8 inch larger than the larger portion of the hole, while the
small end is the same size as the smaller portion of the hole. It is claimed that these treenails, when driven
properly, cannot back out and that they actually hold the planking up against the frame.

All holes are bored, and all treenails are driven from the outside.

William Henry Curtis: The elements of Wood Ship construction ….
Philadelphia, (c1918). 23 cm, 31, 44, 45, 38, 62 pp, ill.

Published by the Education and Training Section, Industrial Relations Group, United States
Shipping Board Emergency Fleet Corporation. Part I-II copyrighted 1918, by W.H. Curtis.

Transcribed by Lars.Bruzelius@udac.se

The Maritime History Virtual Archives | Shipbuilding | Fastenings.

Copyright 1996 Lars Bruzelius. 

Dave Fleming
04-20-2001, 04:03 PM
From an old book on Wooden Ship Building:

Treenails

Hardwood treenails are generally made from selected black locust, and may vary in diameter as driven
from 1 inches to 1 inches, depending upon the thickness of the planking. All treenails, where possible,
are driven through the ceiling inside, then cutoff flush on both ends and wedged with small oak wedges
made for that purpose and called treenail wedges. The wedges must be set across the grain of the plank
through which the treenail is driven. Where treenails are not driven through, a wedge is inserted in the end
of the treenail which, when the treenail is driven, backs up against the bottom of the hole and wedges the
treenail fast.

There are three general types of treenails in use. The first is straight, and is driven in a hole about 1/16
inch smaller than the treenail. When it is necessary to drive treenails of this type longer than 24 inches, it
becomes rather difficult to get them in with the proper amount of drift. Hence, a second type has been
devised where about one-half of the length of the treenail is sized about 1/8 inch smaller than the other
half. These are driven in holes bored first about half-way through the hull with an auger 1/16 smaller than
the large end of the treenail, and the rest of the way with an auger 1/16 smaller than the small part of the
treenail. This in effect shortens the required length of drift and makes it possible to drive much longer
treenails than would be the case with the first type. Such treenails are known as two drift treenails. The
third type is tapered and driven in a two size hole bored in the same manner as described for two drift
treenails. The large end of the treenail is about 1/8 inch larger than the larger portion of the hole, while the
small end is the same size as the smaller portion of the hole. It is claimed that these treenails, when driven
properly, cannot back out and that they actually hold the planking up against the frame.

All holes are bored, and all treenails are driven from the outside.

William Henry Curtis: The elements of Wood Ship construction ….
Philadelphia, (c1918). 23 cm, 31, 44, 45, 38, 62 pp, ill.

Published by the Education and Training Section, Industrial Relations Group, United States
Shipping Board Emergency Fleet Corporation. Part I-II copyrighted 1918, by W.H. Curtis.

Transcribed by Lars.Bruzelius@udac.se

The Maritime History Virtual Archives | Shipbuilding | Fastenings.

Copyright 1996 Lars Bruzelius. 

Jeff Lane
04-26-2001, 01:33 AM
In the well-detailed dissertation quoted by Dave Fleming above, I fail to see how the second trenail type, "two-drift" trenails, have any different driving or interference (called "drift") characteristics than a normal straight trenail driven with the same interference (1/16") along its whole length.

Can someone please explain how, except for a possible inaccuracy in the bored lengths of the two hole diameters, (which might cause an interference of
1/8" instead of the required
1/16" for a short distance near the middle of the hole, making the trenail impossible to drive quite all the way through the hole), there is any difference in the driving difficulty between that type and a straight trenail of the first type mentioned?
Dave, is there a possible mis-quote here? What am I missing?

Jeff Lane




[This message has been edited by Jeff Lane (edited 04-26-2001).]

Jeff Lane
04-26-2001, 01:33 AM
In the well-detailed dissertation quoted by Dave Fleming above, I fail to see how the second trenail type, "two-drift" trenails, have any different driving or interference (called "drift") characteristics than a normal straight trenail driven with the same interference (1/16") along its whole length.

Can someone please explain how, except for a possible inaccuracy in the bored lengths of the two hole diameters, (which might cause an interference of
1/8" instead of the required
1/16" for a short distance near the middle of the hole, making the trenail impossible to drive quite all the way through the hole), there is any difference in the driving difficulty between that type and a straight trenail of the first type mentioned?
Dave, is there a possible mis-quote here? What am I missing?

Jeff Lane




[This message has been edited by Jeff Lane (edited 04-26-2001).]

Jeff Lane
04-26-2001, 01:33 AM
In the well-detailed dissertation quoted by Dave Fleming above, I fail to see how the second trenail type, "two-drift" trenails, have any different driving or interference (called "drift") characteristics than a normal straight trenail driven with the same interference (1/16") along its whole length.

Can someone please explain how, except for a possible inaccuracy in the bored lengths of the two hole diameters, (which might cause an interference of
1/8" instead of the required
1/16" for a short distance near the middle of the hole, making the trenail impossible to drive quite all the way through the hole), there is any difference in the driving difficulty between that type and a straight trenail of the first type mentioned?
Dave, is there a possible mis-quote here? What am I missing?

Jeff Lane




[This message has been edited by Jeff Lane (edited 04-26-2001).]

Dave Fleming
04-26-2001, 02:27 PM
Jeff, to be honest, I did not pay much attention to that statement when reading and then posting the quote.
But perhaps the original writer is referring to what is called 'draw boring'.
A technique of offseting one hole from the other and when driving the trunnel it is supposted to 'draw' the parts tightly together.
Just a quess on my part I'm afraid.
See what happens with language and interpratation over time?
http://media5.hypernet.com/~dick/ubb/confused.gif

Dave Fleming
04-26-2001, 02:27 PM
Jeff, to be honest, I did not pay much attention to that statement when reading and then posting the quote.
But perhaps the original writer is referring to what is called 'draw boring'.
A technique of offseting one hole from the other and when driving the trunnel it is supposted to 'draw' the parts tightly together.
Just a quess on my part I'm afraid.
See what happens with language and interpratation over time?
http://media5.hypernet.com/~dick/ubb/confused.gif

Dave Fleming
04-26-2001, 02:27 PM
Jeff, to be honest, I did not pay much attention to that statement when reading and then posting the quote.
But perhaps the original writer is referring to what is called 'draw boring'.
A technique of offseting one hole from the other and when driving the trunnel it is supposted to 'draw' the parts tightly together.
Just a quess on my part I'm afraid.
See what happens with language and interpratation over time?
http://media5.hypernet.com/~dick/ubb/confused.gif

Jeff Lane
04-26-2001, 05:11 PM
I don't think so, Dave. They use the word "drift" as a synonym for "interference", it seems to me, and they don't say anything about non-concentric holes. Even if they were talking about non-concentric drilling, that wouldn't help to force the plank into the frame; It would be exerting pressure in a direction that would be attempting to split the frame, instead.

I think that the man who wrote it down, or the one who transcribed it, got it wrong. I think, also, that the man who first wrote it wasn't a boat worker, but someone trying to capture what the worker was telling him, and didn't quite understand.

Too bad we'll never know what the worker told him.

Jeff

Jeff Lane
04-26-2001, 05:11 PM
I don't think so, Dave. They use the word "drift" as a synonym for "interference", it seems to me, and they don't say anything about non-concentric holes. Even if they were talking about non-concentric drilling, that wouldn't help to force the plank into the frame; It would be exerting pressure in a direction that would be attempting to split the frame, instead.

I think that the man who wrote it down, or the one who transcribed it, got it wrong. I think, also, that the man who first wrote it wasn't a boat worker, but someone trying to capture what the worker was telling him, and didn't quite understand.

Too bad we'll never know what the worker told him.

Jeff

Jeff Lane
04-26-2001, 05:11 PM
I don't think so, Dave. They use the word "drift" as a synonym for "interference", it seems to me, and they don't say anything about non-concentric holes. Even if they were talking about non-concentric drilling, that wouldn't help to force the plank into the frame; It would be exerting pressure in a direction that would be attempting to split the frame, instead.

I think that the man who wrote it down, or the one who transcribed it, got it wrong. I think, also, that the man who first wrote it wasn't a boat worker, but someone trying to capture what the worker was telling him, and didn't quite understand.

Too bad we'll never know what the worker told him.

Jeff