View Full Version : Frame Socket Bedding Compound

11-01-2011, 03:37 PM
Hi all,

Alright I have a question for the experienced and traditional crowd. As some of you know I am getting near to bending frames into The Maid. I am looking for some answers about bedding compounds and I thought I'd put it in a separate thread to facilitate people searching for the info later.

Background info: The sockets are cut into a fir backbone. The frames are steam bent white oak. They will be silicon bronze fastened into the sockets. Sockets are currently soaked with copper napthenate preservative and they will be sealed with a coat or two of red lead paint prior to receiving frames.

My options as I see them now are as follows:

1) Dolphinite bedding compound. This would require the frame heels to be sealed with paint- red lead in my case. Would it stand up to the time in the steam box?

2) Fiber roofing tar (asphalt based I think). I used this to bed the ballast to the keel. It is real goopy and water proof. Good qualities IMO.

3) A mixture of dolphinite mixed with red lead powder for poison and thinned back to consistency with raw linseed oil. Same problem as 1) but with the benefit of poison.

4) A homebrew mixture of red lead powder, raw linseed oil, white grease, and cabosil or chalk to make it thicker. The grease is to keep it flexible I think.

What sounds like the best option and is there anything better that I missed? What about the issue of painting the frame heels before they get the steam treatment? Does that work? Thanks in advance.

Peerie Maa
11-01-2011, 03:41 PM
You have primed the sockets, so why bed them, worried about poor fit?

Nicholas Carey
11-01-2011, 04:41 PM
You forgot option #5: pitch.

PIRATE (http://www.r-boat.org/) has socketed frames with pitch poured between the floors to seal the sockets and provide a smooth level finish that's easier to clean -- all the little nooks/crannies are filled.

Peerie Maa
11-01-2011, 04:44 PM
^ + 1

shade of knucklehead
11-01-2011, 05:04 PM
The paint won't hold up in the steam box. I use roof cement, but we have used pitch before. Pitch is getting hard to find around here.

However, since they are not going to be removed and you are just trying to fix it so that no water sits in any imperfections between rib and socket why not use something like lifecaulk or 5200? Either one would be neater than tar.

11-01-2011, 05:22 PM
Pitch is often called marine glue and is nearly the same as number 3 roofing tar correct? I will be using something of that variety to fill the voids between floor so water doesn't sit down below the keel where it cannot be pumped out. What I want here is something to have sitting in the socket that I can seat the frame in to make absolutely sure there are no voids. My sockets are good but nothing is perfect and it is a rot prone area so I'm trying to mitigate the risk. So whatever I use needs to go in cold. How about pine tar? I've never used the stuff but it sounds like it could work. I would like to use one of the linseed oil based red lead compounds described above but they are ineffective on unpainted wood. If the paint won't withstand the steam then it sounds like those options are out.

5200 isn't a bad idea. You can't remove the screws from the frame heels without removing the garboard anyway. With the garboard out of the way the permanence of 5200 is not a problem because you can chisel the old heel out just like cutting "new" sockets. And it would give a bit of strength to that connection. I don't really like 5200 though on traditionalist grounds. I'll have to think about it.

Peerie Maa
11-01-2011, 05:34 PM
Marine glue is pitch mixed with other ingredients. Pitch is a distillate from coal, coal tar stays runny, pitch sets hard. Pine tar is also liquid, and may be too thin for your purpose. Are you going to set your garboard in something as well?

shade of knucklehead
11-01-2011, 06:55 PM
The reason I mentioned 5200 is because my rule for using it is it has to be in a spot that is going to be permanent. To change the rib end in the socket you have to remove not only the garboard, but also the rib. So its pretty much a permanent part of the boat, something that is not really designed to be replaceable.

Nicholas Carey
11-01-2011, 07:03 PM
Marine glue is pitch mixed with other ingredients. Pitch is a distillate from coal, coal tar stays runny, pitch sets hard. Pine tar is also liquid, and may be too thin for your purpose. Are you going to set your garboard in something as well?Pitch is hard to find, but it's a "marine store" like pine tar that's distilled from pine sap, though Wikiepedia tells me that it's also made from coal and called bitumen.


The stuff not only sets up hard, but it's crystalline. Shatters all shiny and sharp-edge like glass, it does.

You can buy navy pitch and proper pine tar from Auson (http://www.auson.se/) in Sweden: http://www.auson.se/content/view/74/34/lang,en/. Their navy pitch is a mixture of bitumen and pine pitch. Their complete list of pine tar products is at http://www.auson.se/content/blogcategory/19/34/lang,en/. One of them is #502, old-school traditional pine tar that is a byproduct of charcoal burning: http://www.auson.se/content/view/72/34/lang,en/

Auson's distributor for USA is Noxudol USA (http://www.noxudolusa.com/). Here's their list of Auson's pine tar products: http://www.noxudolusa.com/pine_tar/pine_tar_products.html. Interestingly. Noxudol seems to have sub-distributors in Canada, Mexico, Japan and El Salvador.

Edited to note: Auson pine tars are also available from http://www.solventfreepaint.com/pine-tar.htm. Another traditional Finnish producer is at http://www.hautaterva.net/ (but you'd better be comfortable with reading Finnish).

wizbang 13
11-01-2011, 08:12 PM
I used to see West Indian chippys using pitch.
Yup,It was like a block of black glass. They heated it and added "coal tar". The coal tar softened it. too much, too soft, yuch.
They used it for deck seams .

11-02-2011, 10:35 AM
As Frame socket have a reputation to be a nice place for rot to start, I would put something really toxic there to put all the chance on my side. For this reason I would stay away from 5200. Pitch with tar, or a mix with Red Lead would be a better choice.

As you have access to Dolphinite, mixing it with Red lead powder can be a nice mix. As you also put steam frames in, I would let them higher then deck level during the building. At the top drill a big size hole and fill this with poison, the poison will run slowly down the grain, keep filling until you see it at the bottom (Which take months). When you will cutting the top for putting the deck on, you will have rot proof frames...

Just a Idea... That's how I would do it...

11-02-2011, 12:38 PM
I've heard of that solution before as well. I think you need absolutely straight grained framing stock or the run out would leach your poison out the side of your rib. I think I saw this in relation to mast building rather than frames but the concept is the same.

Mad Scientist
11-02-2011, 01:54 PM
JoshuaIII's frame treatment has been mentioned before on the Forum, but for Red Oak frames (and different goo). You're using White Oak for the frames; I don't know if the toxic goo will flow through White Oak.


wizbang 13
11-02-2011, 03:05 PM
One could make a small angled bore into the frame near the bottom to pour in the poison.
But won't the stuff that is going into the spaces between the frames encapsulate the frame heels ?
Can you leave a foot or two sticking out of the steamer? So as not to cook out the poison. Not much bend there. Set the bottoms of the frames in a bucket of the copper napawhozit before steaming. I may be over thinking here.

11-02-2011, 03:30 PM
One could make a small angled bore into the frame near the bottom to pour in the poison.
But won't the stuff that is going into the spaces between the frames encapsulate the frame heels ?
Can you leave a foot or two sticking out of the steamer? So as not to cook out the poison. Not much bend there. Set the bottoms of the frames in a bucket of the copper napawhozit before steaming. I may be over thinking here.


The yet to be determined tar/pitch/cement substance that I use to fill in the spaces between floors will go in after planking. It will fill up the area to the top of the keel timber. You can see from the picture that water will get trapped between the frames so something is needed to keep the water up high enough so that it can flow through the limber holes in the floor. Whatever substance I end up putting there along each side of the keel will not serve the same purpose as what I am looking for now, which is a bedding compound to go actually in the sockets that makes sure there is no small voids lingering down inside there.

I probably will try the poison trick- although I don't think you'd want to do that on a boat you would be living on. The poison gives off fumes throughout its active life. I'd rather just poison each end where it is most rot prone and use something less toxic on the rest (paint, pine tar, etc..)

I have thought about leaving the very end out of the steam box so it could be poisoned and painted, but the most severe bends are in the tuck 6-10 inches from the end so I don't think I can get away with that. Maybe I could just leave the last two inches of frame sticking out- that is all that beds in the socket anyway and that part shouldn't ever need to bend. If I go that route I will use the dolphinite with red lead powder mixed in.

Does fiber roofing tar need painted wood or can it go on raw wood? I mean the stuff that is asphalt based and thick and goopy at room temperature, used for leaking roof repairs. Does it have the needed poisonous characteristics? If it can go on raw wood and if it is somewhat preservative I will probably use that. Thoughts?

And someone asked earlier if I was going to bed the garboard- the answer is probably not, no. But that fit is easier to get perfect using paint and slow work with hand tools and it will be sealed as discussed above using pitch or tar.

11-02-2011, 04:07 PM
I think Pitch is the perfect solution for that application.
In my experience boat pitch is not roofing tar. It smells like turpentine when heated, it will shatter if struck with a hammer and bend like taffy at the same time. As sticky as can be when warmed up. If it is broken in place (very unlikely) a quick play with some heat will put it all back together.
(My best guess is a blend of pine pitch, beeswax and perhaps some gum arabic).

With the finished boat on it's lines I have melted it and poured it all around and into awkward areas that can't be limbered much like you show in your image. It is wonderful stuff, will keep the water out, then there is no problem with rot spores and the rest.
Hamilton marine has it listed as Marine glue, but it is boat pitch, the real stuff with instructions...

11-03-2011, 06:36 PM
I think Pitch is the perfect solution for that application.

It sounds like just the stuff to pour into the bilge after planking. How would I use it in this application of bedding the sockets? Could it be heated to a semi-thin but not runny consistency and troweled into the sockets before knocking a frame heel in there and bending it in? The appeal of the cold application roofing tar is that it is the perfect consistency for bedding at room temperature. But I don't know if it has the preservative qualities (I suspect it does) or if it will work on raw wood.

wizbang 13
11-03-2011, 06:59 PM
Here is something You may want to consider.
The Asphalt goo, (it is confusing, the different names), may "float" out a bit, on top of any bilge water, in essence, make a forever "oil slick" down there.
Pitch, as I know it , will harden up. Less apt to spoil the bilge water.
As I mentioned earlier, I have seen coal tar mixed with it when heated. The coal tar,(whatever THAT is, )may do the same thing, it is very yucky.
As one changes latitudes, warm n cold water, the pitch gets harder and softer, depending on the ratio of coal tar to pitch. So, you may get different behavior in the Sea of Cortez than the Columbia River.
More questions than answers again.
sadly, I am not up to speed on the ratio, I was just checking out trad 3rd world building earlier in my youth.
I used the asphalt goo in the gasket between my wood keel and ballast keel, 27 years later, it still ouzzes out in a hot (Caribbean) boatyard.

11-03-2011, 08:12 PM
Don't all the connections and joints on a wood boat "work" all the time? In which case sealer/bedding would need to have some flex to prevent separating at some seam or face and opening a one-way path to water. The flex would need to be sufficient to avoid stressing any face or seam beyond the shear strength of the bedding.

In particular, a long thin "glass like" run of pitch in the bilge would seem to invite cracking when the whole boat worked along it's full length in heavy weather. I'm no way an expert here, but surely the bow and stern will twist and flex an inch or so relative to one another in a 30' boat? How much and where to the ribs flex when tacking hard?

Just a thought from the peanut gallery.

Cheers, Rufus

11-03-2011, 10:33 PM
Not much of an educated opinion, but this really is the proper place for 5200.

I don't like the stuff either. It's too permanent. But I think that's beneficial here. It has the slight flex needed, and will seal well. If these frames ever have to come out, that goo will be the least of your concerns.

Capt Zatarra
11-04-2011, 12:05 AM
I have some info that might help. Here is an old recipe for pitch that I was given about 30 years ago. I was told that it is hundreds of years old.
1 part bees wax
1 part pine tar
1 part dry clay powder

I have made it like this
1 part paraffin wax
1 part motor oil
1 part red ball clay powder

The thing to do is melt the
wax in a large metal can(I used a garbage can on a crab pot cooker in the drive way, we were making 30 gallons) once the wax is melted use a paint stirrer in a drill to stir the oil into the wax. Once it is mixed start sifting in the clay while you stir. It has to be hot while you mix it.

To test it, drip a tablespoon size glop into room temp water to cool it off, DO NOT LET IT TOUCH YOU WHEN IT IS HOT! It will stick to your skin and burn the @# out of you. roll the sample between your fingers, if it is too dry add more wax and oil. If it is too sticky add more wax. If it is to brittle add more pine tar/oil. when I did it I made a mold of a sheet of plywood with a 2x4 clamped around the edge. When it cooled I removed the 2x4's and used a square end scoop shovel to cut it into brick size pieces for easy handling later.

This is poured in to the bildge hot. It will soak it any seams and cracks and seal out any water penetration. If you have the mix right it will work with the boat and not crack with the shrinking and expanding of the boat. My plan for my boat will be to make a patch without any clay for the first coating to get the max penetration. Then the thicker pitch with clay to fill up the bilge to the limber holes.

I will be also adding some sort of poison in the first coat, which will be sealed under the thick layer. Hope this helps. Capt. Z.

11-04-2011, 12:38 AM
JM, My vote would be for Dolfinite, after the sockets have been primed with red lead primer or the like, and a splash of Cupernol on the lowest 6" of the frame before steaming( steam the whole thing, you need every bit of flex you can get...) old timers would sozzel the whole frame in the pungent Green Death, but I can understand how you might want to avoid that. I have never actually seen rot in this area, frame ends get soft and eroded away from living in the wet salty bilge, but I don't see lots of rot... Pitch is very useful, but only once everything is in place to improve the water flow and prevent permanent puddles. Cheers, Steve/BT

11-04-2011, 01:10 AM
Hey Cap'n that is quite the recipe. I like it and will definitely keep it in mind for later. I like the pine tar version best as it seems more preservative than the motor oil version.

boattruck: I like where this is going. Will a frame soaked in Cuprinol (or whatever its called now) resist from leaching the oils out of the dolphinite? It would be much better than raw wood I am sure. The cuprinol itself is quite oily, but my experience is limited to freshly applied stuff. I would probably let the frames ends soak in a coffee can of poison and really get them saturated. Then once they are "dry" I would steam them and install in dolphinite. Good plan?

Capt Zatarra
11-04-2011, 02:20 AM
There are five or six grades of pine tar. I don't remember right off the top of my head, But I think #0 is the finest, lightest, honey colored, grade. #5 is thick and black. For this recipe you want the #5. I would not use the motor oil recipe in any boat where you care how it smells! The smell is still there 10 years later. Capt. Z.

willin woodworks
11-04-2011, 06:21 AM
Bees wax and linseed poil makes a great wood sealer on itz own. Melt together in any number of combinations from stiff like shoe polish to mushy like grease and it can be rubbed on, painted on, poured on. I have a coffee can full of it that is putty consistency on the bench for dipping screws into prior to driving them in tough stock. It never goes bad, it wont contaminate a varnish finish and if nothing else it smells "boaty".

Add pitch and you've got a sealer that when slopped on hot will soak it and then harden and set. Pitch comes in a number of formulations from "dead Level" to "steep" and any commercial roofer can get you some.

Dip the frame ends into it while it bubbling hot and the chances of them ever rotting are slim to zip. Paint it in the sockets and set the frames hot from the steam box and you're all set.

Be careful when you're melting real ptich. many people have an adverse reaction to the smoke. It can leave a red rash like sunburn that can be pretty uncomfortable for a couple of hours. Do it outdoors and stay up wind until you're sure you wont react to it.

11-04-2011, 06:17 PM
JM, The Cupernol and the Dolfinite get along great, we often mix a few capfulls of Cupernol into our fresh can of Dolphinite to simulate the old formulation, as well as to loosen it up for spreading on the chilly mornings... Soaking the frame ends won't hurt anything... Cheers, Steve/BT

Jay Greer
11-04-2011, 07:45 PM
In this, I am seconding the use of bee's wax which has already been mentioned. While everyone has their personal favorite, mine is bee's wax that is melted and poured in once the garboard is fastened. I have worked on boats that were nearing 100years in age that had frame sockets and keel rabbet ledges filled in this manner that were as good as the day that the wax was poured. Bee's wax and honey as well are a natural ancient antiseptic that has been used since the time of the Pharaohs and wise Chinese physicians. Today, modern medical researchers are taking a second look at this natural miracle product. Honey and also bee's wax will not support either bacteria or mold spores! It is simple and foolproof. When poured in hot it will fill every void, nook and cranny sealing them against rot and moisture intrusion. And, if you choose to use it, you are helping to support your local bee keeper as well. Just note that the honey should be left out of the equation.

11-05-2011, 11:12 AM
Jay, But if you add the honey( in moderation ) to the toast, tea, or both, of the boatbuilder, that isn't too bad either...you mending well? Hutch/BT

Jay Greer
11-05-2011, 11:14 AM
Thanks Hutch,
Things are looking up!

11-05-2011, 11:57 AM
Good to hear, Cheers, Hutch

Gold Rock
11-05-2011, 03:24 PM
This suggestion isn't based on direct experience, but if you all remember an article in WB some while ago on shellac, I recall that NGH used a very thick cut to bed between the skins of some of his double planked boats and that after many, many years, repairs showed this stuff to be amazingly 'as new', if you will. Would a very high viscosity cut of shellac be of value? I've used the stuff professionally for many years as a surface finish on wood patterns and my experience with the once-dissolved flakes recongealing is that they reform to a flexible, kind of plasticy solid. I've never let the stuff sit long enough to see if it eventually rehardens to a brittle state but the aforementioned NGH anecdote would suggest that it does not. But again,of course, I'm not claiming expertise here.

Jay Greer
11-05-2011, 10:48 PM
Indeed, Nathanial Herreshoff as well as many other boat builders have and continue to use shellac as a bedding and double planking luting compound. Shellac posseses several desirable properties that are well suited for boat building. In the case of double planking it can be mixed almost to paste consistancy and will allow ample time for fastening of the laminate before it sets. Under sheer loads, very desirable for double planking, it is highly resistant to inertia which creates a stiff hull. Strapping was also used, by Herreshoff, with this form of construction. Perhaps the most desirable and forgiving quality of shellac is that it can be easily re-disolved with denatured alcohol should it ever need be disassembled, something that is impossible with such products as 5200.

11-06-2011, 10:19 AM
Gotta agree with Greer....BTW how are you doing?.......Bees Wax is the best. I pour it in most every space where moisture can get to and I can't. My bilge never has a puddle and water flows from the bow right to the pump. Easy, self leveling, flexible, reseals with a little heat, natural.......all that is good and needed for this purpose.
Good luck

Jay Greer
11-06-2011, 12:34 PM
I'm ok Lars. To quote Monty Python: "Feeling much better! Not dead yet you know!"