Clinker Launch

[lexi]

Ok guys, many thanks.

[Peerie Maa]

By the way, hole diameter for nail size is normally from flat to flat...the corners are left to bite into the wood in a slightly smaller hole than the square nail shank.

Circle below is drill / hole size. Square is nail.
Attachment 60567

That depends on whether you are driving through oak or softwood. That diagram is correct for oak and other hardwoods but for softwood you use a smaller drill, diameter = half of the diagonal dimension of the nail.

[lexi]

A few general questions. Instinct tells me to put the best planking on the bottom boards. However my bottom boards will painted. The bright boards above water line, look better with cleanest timber. I have a cubic metre of larch . Like any tree I suppose, some of it is much cleaner than the rest. I know about ducking and diving with plank shape to avoid knots on plank edge etc. Is it better to use a few boards with knots and cut out and plug/ paint on bottom boards? The knots I speak of are maybe just more than half inch.

[lupussonic]

Using planks with knots in depends if they are tight or loose. Obviously loose knots must go and be replaced by graving pieces otherwise known as Dutchmen, but I'm guessing you would not want those to be finished bright above the WL. I'm a working boat guy, and have no such qualms, in fact I'd probably put the best pieces below the WL for peace of mind, and any that need Dutchmen above, and wear them with pride.

[lexi]

Using planks with knots in depends if they are tight or loose. Obviously loose knots must go and be replaced by graving pieces otherwise known as Dutchmen, but I'm guessing you would not want those to be finished bright above the WL. I'm a working boat guy, and have no such qualms, in fact I'd probably put the best pieces below the WL for peace of mind, and any that need Dutchmen above, and wear them with pride.

Thanks Lupo.
I got a log that was long enough to avoid scarfs. I can see that many boats of 16 and 17 ft probably have scarfs because although their planks may have been long enough, it may not have been clean from one end to another..........hence a scarf. Still learning

[lexi]

This is the good and the not so good. The better looking plank is 3" thick and about 18ft long. The plank with knots is about 1 1/8th thick and 18ft long and 4 or 5 of those.

[Peerie Maa]

This is the good and the not so good. The better looking plank is 3" thick and about 18ft long. The plank with knots is about 1 1/8th thick and 18ft long and 4 or 5 of those.

I have seen knots like those fixed by being bored out and bunged with a dowel glued in, sometimes the dowel is split and wedged with the wedge laying across the grain of the plank. That would be overkill for epoxy glue though.

[lexi]

I have seen knots like those fixed by being bored out and bunged with a dowel glued in, sometimes the dowel is split and wedged with the wedge laying across the grain of the plank. That would be overkill for epoxy glue though.

Better to plug it on the final thickness Nick? Or plug at 1 1/8" then rip it down middle and final plane with the plug already epoxied in?

[lupussonic]

I plunged routered out knots in my solid larch masts and bunged with epoxy. I would try doing that before final planing down to size. You'll get a better smooth finish, but do a test first to see if they ping out in the thicknesser.

Nicks mileage may vary.

[Peerie Maa]

I plunged routered out knots in my solid larch masts and bunged with epoxy. I would try doing that before final planing down to size. You'll get a better smooth finish, but do a test first to see if they ping out in the thicknesser.

Nicks mileage may vary.

It depends on what tools are to hand. A Japanese pull saw followed by a sharp low angle block plane will give a good finish, probably better than the ripples of a thickness planer. However, if all Lexi has is a European saw and a bench plane your way may work better.

A test on some scrap is called for.

[lexi]

Ok guys. Will try some tapered plugs as well.

[lexi]

Talk to your sawyer about the thickness of his saw kerf, and see if he will plane it for you. That way you can have confidence that he will thickness to your 7/16ths when finished planing. Do not ask him to saw to 7/16ths as the sawn plank may come off the saw at 5/16th before planing.
You might find it easier putting a scarf in that garboard and the next strake as they both land on the sternpost.

Nick: Can you elaborate with a sketch of what you meant here?

[Peerie Maa]

Nick: Can you elaborate with a sketch of what you meant here?

Both ends of the strakes that land in the rebate of the sternpost have to fit at both hood ends, the stem rebate, and the stern rebate. This is tricky work to spile and cut on planks that will be bent and twisted, as one cut too far creates a bad fit that cannot be put right.
However with a mid-length scarf, it will be much easier to fit the hood ends into the rebates accurately, then cut and fit a scarf in the middle of the strake.

[lexi]

Both ends of the strakes that land in the rebate of the sternpost have to fit at both hood ends, the stem rebate, and the stern rebate. This is tricky work to spile and cut on planks that will be bent and twisted, as one cut too far creates a bad fit that cannot be put right.
However with a mid-length scarf, it will be much easier to fit the hood ends into the rebates accurately, then cut and fit a scarf in the middle of the strake.

See what you mean. In my naivety, I thought scarfs were something to be avoided like the plague. That was why I searched to get a long log of Larch. My old boatbuilder friend who died last month at 92 used to say there was nothing wrong with a scarf done proper. I got the garboard plank and next 2 strakes out intact. The garboard I have made a copy of, in thin door skin. I was going to use that full, but will have your suggestion to fall back on should that not go well.
This pic shows a problem to me: That strake after the garboard? It has a horrid long spike tapered to nowt. The 3rd strake is a very broadstrake, so probably limits what can be done to alleviate that problem? I think that has been a compromise of the design? ie having the 10 planks on the boat in that shape or configuration. Any thoughts on that?

[Peerie Maa]

See what you mean. In my naivety, I thought scarfs were something to be avoided like the plague. That was why I searched to get a long log of Larch. My old boatbuilder friend who died last month at 92 used to say there was nothing wrong with a scarf done proper. I got the garboard plank and next 2 strakes out intact. The garboard I have made a copy of, in thin door skin. I was going to use that full, but will have your suggestion to fall back on should that not go well.
This pic shows a problem to me: That strake after the garboard? It has a horrid long spike tapered to nowt. The 3rd strake is a very broadstrake, so probably limits what can be done to alleviate that problem? I think that has been a compromise of the design? ie having the 10 planks on the boat in that shape or configuration. Any thoughts on that?

How old is the boat? That tapering hood end worked for that length of time without failure.
As she is clinker it is less of a problem than if she were carvel.

[lexi]

Ok Nick. Point taken. Boat must be 60 years plus.

[Alan H]

The level of knowledge and craftsmanship in this thread is inspiring.

I will never do this, but I wanted to write something.

[lexi]

The level of knowledge and craftsmanship in this thread is inspiring.

I will never do this, but I wanted to write something.

Very nice of you to say that Alan. My trade skills lie elsewhere really but they help in trying to build most things and to keep learning.

[lexi]

Is this a catch 22? I have a quarter sawn plank that may do for the first pair of garboards. However, there is another clean clean plank that could give me the first 2 pair of broad strake. But,the board is slab sawn. Tell me: Quarter sawn is best but is it best when edge setting and twisting to shape? Suppose rift sawn is maybe best compromise when twisting a plank.

[Peerie Maa]

Is this a catch 22? I have a quarter sawn plank that may do for the first pair of garboards. However, there is another clean clean plank that could give me the first 2 pair of broad strake. But,the board is slab sawn. Tell me: Quarter sawn is best but is it best when edge setting and twisting to shape? Suppose rift sawn is maybe best compromise when twisting a plank.

I don't think that builders bothered. They stickered the log in two stacks, so that the book matched part of the tree were used for the same pair of strakes. That way they maintained symmetry of the woods behaviour and stresses.

[lexi]

Thanks Nick. I have been avoiding the white coloured sap wood that goes from bark in about 2 inch. On the Larch, that wood is pretty hard with a lot of growth rings on it? Is any of it usable?

[Peerie Maa]

Thanks Nick. I have been avoiding the white coloured sap wood that goes from bark in about 2 inch. On the Larch, that wood is pretty hard with a lot of growth rings on it? Is any of it usable?

It will be as strong as the heartwood, but full of food for bugs and rot fungus, so try to avoid it if you can.

[lexi]

Hood ends? Don't know whether to screw or nail 'em. I'll be using bronze screws where the garboard fixes to dead wood. Screwing the hood ends looks garish on a small boat? Scottish and Irish small clinker boats usually have copper nails on the ends. 7/16" plank. I am going into lam oak stem and solid oak stern knee. Same gauge nail as plank or the heavier nail ( 11g) that is going through plank and rib? Nail will be slightly skewd for grip I suppose?
Hand sawed down the middle for first pair of strakes (garboard) Hard going that Larch. Maybe because the plank was quarter sawn?

[Peerie Maa]

It is up to you. These days folk use bronze screws for the hood ends, but copper worked for ever, Just ensure that you use the correct diameter drill for the pilot hole in the oak. If you want more grip rag the nail by raising burs on the square edges with a sharp blade.

[lupussonic]

Screws for me. Better holding where the most stress to pull out occurs. But for Christs sake clock them or Mr Ledger will have your hide.

[lexi]

Screws for me. Better holding where the most stress to pull out occurs. But for Christs sake clock them or Mr Ledger will have your hide.

Take your point Lupo and do agree.Will mull it over. Maybe screws have more tendency to split a plank end? Ie when putting pressure on the countersink? Will do a few samples off boat with scrap. Only guessing that Mr Ledger is an OCD thing?

[Peerie Maa]

Take your point Lupo and do agree.Will mull it over. Maybe screws have more tendency to split a plank end? Ie when putting pressure on the countersink? Will do a few samples off boat with scrap. Only guessing that Mr Ledger is an OCD thing?

Just ensure that the pilot hole, the drill for the shank through the plank and the countersink are just so and you should be OK.

[lexi]

Still plodding away. One of my planks cut through in half with hand saw. I go from around 30mm down to 14mm then run them through my cheap thicknesser. Heavy sawing that is.

[Peerie Maa]

^Way to go.

[nedL]

Good work! (Though sort of the hard way to get there, but if that’s how you have to do it, then that’s how you do it.)

[lexi]

Ribs. I am going to buy Prime Euro Oak ( kiln dried) for the ribs. Cannot get suitable green or air dried around here. We have Scottish Sissal Oak, but every bit I have sampled is hipster wood with gnarly twist. Engish Oak is a lottery as I would be buying blind and from distance. So, I can pick through planks of Polish Oak here and get any grain I want and consider the way I am going to break the ribs out from planks. When you look at the top end grain of the rib fitted on the boat, what is best way for the grain to be? Which way will make easier bending and give strength and resistance to split?

[Peerie Maa]

John Leather in Clinker Boatbuilding is silent on grain orientation. As the ribs are sawn out of boards that are cut from the log through and through rather than 1/4 sawn you get all orientations.
John Leather talks of planing one edge of the board along the grain, then scribing and sawing the first rib, then planing and sawing again, and so on.

[lupussonic]

I would have the grain in line with the gunnel, if looking down at the end grain from the top of the rib. It stands to reason that the natural laminations in deciduous wood will bend better this way. Think of a laminated frame bent in, and place your grain in the same way. It will give you an easier time both for fitting and you will have less breakages. Just try to avoid too much grain run out, but as ever, compromises rule supreme.

[lexi]

Thanks fellas.

[nedL]

The grain in the ribs of my various boats seems to run in all direction, and I have never paid too much attention and have not noticed a success/failure that I can attribute to orientation.