About Weldwood. . . and boat length. | SouthernPaddler.com

About Weldwood. . . and boat length.

FlaMike

Well-Known Member
Jun 20, 2007
624
2
Spring Hill, FL
www.ptponds.com
I know this isn't a very popular subject, as epoxy is the accepted "go-to" glue (and sealer) these days, but it is my intent to go a little more "old school." Can't seem to explain it very well, and have given up trying to, but it is what fascinates me right now. I hope someone who has used Weldwood will chime in here.

Looks to me like some of the discussions I've read on Weldwood, mostly on other forums I have to say, were flawed because they often discussed problems with it without taking into account that there are several different versions of Weldwood. The one currently found in most stores, especially the big-box places is a neoprene-based contact cement. It's the least water resistant in the group and is an "instant-grab" glue. Kind of hard to make adjustments once the two pieces have made contact. This one is in a red & black can.

The labeled as a marine version looks to be the same stuff that marine plywood is bonded with. Green & white can. The most water resistant of the lot, but it requires much more bonding pressure than it practical for building small boats. Pretty pricey, too.

The one I now think is the right one is Weldwood Plastic Resin Glue, in the white & tan tub. This one falls in between the the other two as far as being water proof, doesn't require nearly the clamping pressure as the Marine version, and it matches the description (a tan material, with a urea formaldehyde formulation,) that I've read about in older boat building books.

I'd like confirmation on what I think I know. Or a correction if I got it wrong yet again.

Also, I'm not sure just how much I'll need. Price isn't an issue, but if I buy too much, it's rather short shelf life might make whatever's left over useless on the next build. Keith's 12ft Swamp Pirogue plans specifies Weldwood, but not the amount. It comes in both a 1 lb and a 4 /2 pound tub. From Jamestown Distributors, that would be $8.99 and $29.01 for the respective sizes. Maybe two of the 1lb tubs?

Still planing on using epoxy for the scarf joints in the ply, unless an experienced builder can recommend using the Weldwood for that too. Won't need a scarf for the rails or chines, as I got with the local cypress mill and they can supply the full length pieces I'll need. And I do know that my joinery will have to be good and tight, as I won't be depending on thickened glue to make up for leaving any gaps.

Still planing on two, back to back builds. One being Keith's Swamp Pirogue plan, the other a version of Keith and Seedtick's Marsh Pirogue. Still trying to decide on making them both 12ft, might build the swamp style per plan and then decide if I should bring the marsh pirogue up to 14ft or not. And I have to admit I have considered adding 2ft to the middle of Keith's plan, but that comes mighty close to sacrilege somehow.

The motivation here is that my 170lb weight would be just fine in either design at 12ft, but the other potential "captain" or sometimes "crew," is a bit weightier at maybe 240lbs. (Of course, I am NOT necessarily talking about my, or any other's wife here! That would be wrong. . .)

Mike S.
Spring Hill, FL
 

Wannabe

Well-Known Member
Apr 5, 2007
2,645
2
on the bank of Trinity Bay
About forty years ago one of our crewboats had a wooden entry hatch which was broken. I repaired it with what I remember as plastic resin glue. A whitish or tan powder and I mixed it with water to glue the hatch back togeather. That was some good glue.
Bob
 

seedtick

Well-Known Member
Jul 22, 2006
1,161
7
Denham Springs, LA
Mike,
I think you're correct in your assessment. The typical "weldwood" was a tan powder and mixed with water to make a brown glue. It has been used at least as far back as the 50's and has glued many a boat together satisfactorily. It was used because it was the best they had. Friend Keith and I used it in the early years because that's what the old folks that taught us used. We now use epoxy because we believe it's better. Not that weldwood is bad, just that epoxy is better.

The downside of weldwood is that it's brittle (it's also an upside because you can break the joint without destroying the wood). Another downside is that it does not fill gaps near as well as filled epoxy. you have to have good joints to get a good grip. No problem for master boat builders, but amateurs in a hurry would rather slap on a layer of epoxy peanut butter knowing that it will hold instead of taking the time for a good fit. The main downside for us is pot life, a slow cure epoxy has significantly more pot life than a batch of weldwood

two people are a lot more comfortable in a 14 footer
 

FlaMike

Well-Known Member
Jun 20, 2007
624
2
Spring Hill, FL
www.ptponds.com
MM, Old Sparkles, agree about DuckWorks! But I'll have to wait for "permission to join" their Yahoo groups page to see that link. I signed up, just waiting to hear from them.

Wannabe, that's a pretty good recommendation. I have read quite a few like it on other forums. Always looking for more input like that.

Seedtick,

You have to know that I always want your opinion, particularly on subjects like this one. Just when I think I've finally figured something out, along comes more information and I'm re-evaluating again. Just because I seem to have a one-track mind, it doesn't follow that I can't hit a switch and move over to another rail. . . :D

Other than trying to raise my level of craftsmanship as I'd have to with the Weldwood, pot life was an additional reason I'd decided to go with the Weldwood. I just double-checked the DAP and Raka websites and I'm kind of at a loss here. Of course, they don't make it easy by giving the pot life estimates at the same temps. DAP gives their product a pot life of 2.5hrs @ 80*F. Raka says their "slow hardener" provides a pot life of "more than 25 minutes" @ 77*F.

This is why I thought Weldwood would give me more working time. But if your experience tells you otherwise, I do believe I'd defer to your advice. And if that is the case, any thoughts on how much epoxy I'd need to build one or both of those pirogues? With or without the "skim coat" on the outsides?

I realize the cost of the glue would go up quite a bit, but the overall cost to build wouldn't be all that much more, so that wouldn't be a problem.

Oh, one more question if I may, if, (just suppos'in,) someone was to stretch out Keith's 12ft pirogue plans and build a 14 footer instead, (just suppos'in!) any chance that someone might get a visit from the Cajun Mafia and maybe wind up with his legs bending the wrong way? Hey, just ask'in here. . . :roll:

And I have located a fairly local source of marine ply, and it's a Douglas Fir ply, probably the same as you use. I'm going with it.

Mike S.
Spring Hill, FL
 

seedtick

Well-Known Member
Jul 22, 2006
1,161
7
Denham Springs, LA
maybe my remembering isn't what it's supposed to be or maybe we mixed it a little thicker than recommended so it wouldn't run down a vertical surface, but I don't remember a pot life anywhere near that.

I do remember trying different adhesives like 5200 and a polyurethane something or other, but when we got to epoxy, we never went back

we don't use raka, we use west systems, I really like the pumps. Never really measured how much epoxy you use for glue, but i'd guess a quart size would easily glue up 2 or 3 boats. Realize that i'm talking about gluing and not using it for fillets.

stretch away, one of the good things about building your own is that you can make it larger or smaller in any dimension
 

FlaMike

Well-Known Member
Jun 20, 2007
624
2
Spring Hill, FL
www.ptponds.com
OK, you have me thinking now. . . Maybe "sticking" (sorry 'bout that!) with epoxy is something I just might be better off with doing. In fact, I probably will.

So, I'm wondering if you still use the boat nails spaced 1 1/2" apart as if you were still using the Weldwood? Or do you now use the nails more or less as-need? I suspect that the metal fasteners could all be removed and the holes filled, but I'm not sure I really see the need for that. I don't feel the need to remove them just so I could say "no nails included."

I'll leave you alone for now. . .

Unless you'd like to answer a stem question, that is. . .

In your DU marsh pirogue build, was the stem tapered like Keith's swamp pirogue plan? I haven't forgotten that the marsh pirogue stem is curved, but I do recall someone, beekeeper or jdupre', mentioning a curved and tapered stem.

I'll back off for now. But probably not for long! :D

Mike S.
Spring Hill, FL
 

seedtick

Well-Known Member
Jul 22, 2006
1,161
7
Denham Springs, LA
we use ring shank nails in addition to glue, belt and suspenders approach

curved stems are not tapered, beekeeper had a recent post on curved stems
 

FlaMike

Well-Known Member
Jun 20, 2007
624
2
Spring Hill, FL
www.ptponds.com
Thank you sir. Oddly enough, I've run out of questions! :lol:

After re-reading just about every thing you've written on the marsh pirogue, I now know where I was going wrong in shaping the side panels and I have just one more model to build to prove it. And that model will also show me how to get the sides out of a single sheet.

Mike S.
Spring Hill, FL
 

beekeeper

Well-Known Member
Mar 4, 2009
1,917
59
seedtick said:
we use ring shank nails in addition to glue, belt and suspenders approach

curved stems are not tapered, beekeeper had a recent post on curved stems


Most of my curved stems have been tappered. I like the sealed finished look and I think it makes for a stronger joint. Drawbacks are it is heavier, takes longer to make, and is not traditional or needed. See this post:
beekeeper said:
seedtick said:
flip the stem on its backside and draw a line down the center

lambertpro2010016.jpg


I did my first ones like that because that is how you and Keith showed me. When I made the ones for my pirogue I made them to fit to the sides (not stand proud).

IMG_1560.jpg


To do that I use a piece of wood 3 &3/8" wide and 2 & 3/8" high.
I mark two lines 3/16" each side of the center line shown in your picture and cut to those lines. That leaves a 3/8" face on the stem instead of being pointed. The sides of the boat are planed flush with this, leaving a flat area to attach the batter board. The flat on the front of the stem helps me face the sides aligned properly and flush (not rounded over).

Thanks for posting this and all the sharing you guys do. :D
beekeeper

I like Titebond 111. Waterproof, no pot life issues, water clean up, and only around $20 per gal.

beekeeper
 
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FlaMike

Well-Known Member
Jun 20, 2007
624
2
Spring Hill, FL
www.ptponds.com
Thanks, beekeep!

Although I appreciate the info (very much!), I'm going to go with the non-tapered curved stem on the marsh style boat, and follow Keith's plans for the tapered, straight stem on the swamp style. If I do another one with a curved stem, I'll likely give your tapered version a try.

And after too much deliberation, I think I'll use epoxy for the glue, rather than Weldwood for these two builds. Still might try the Weldwood on some much smaller boats, as I have been looking at the Mouse series by Gavin Atkin. Also been looking at the Bolger designs on Payson's (RIP,) Instantboats web site.

Thanks again,

Mike S.
Spring Hill, FL