Hey, fellow boat builders, I started my Weekender today and its been fun from the first cut. Just have a quick question about glue. Is Weldwood Plastic Resin glue good enough. Back on the farm if something needed gluing we just drove in another 20 D. Also second question; How much should I order? Plan calls for 2gal but its sold by the LB. Any help woul be appreciated...Jim Stewart
I would suggest you use epoxy and add fillers to it as needed for gaps and holes. There are hundreds of posts on the forum dealing with the matter and though there are people who used other then epoxy I think the vast majority ended up going to it eventually. Paul Riccelli and a few other experts on epoxy have described in detail the many advantages and methods for using epoxy. Give it a search.
I started my boat with very limited epoxy knowledge and ended it with enough information and experience to earn and advanced degree from someplace. It is amazing what you can do with it and the joints I made for tests purposes always ended with the wood breaking not the glued joint. You can mix in wood flour, talc, sawdust, metal dusts, micro-balloons to form bondo and about anything else you can think of. I used screws to hold some parts as well as the epoxy but think I could have removed them with very little chance of the joints failing. If I were to build another I would be tempted to removed the screws, after the epoxy hardened, drill out the holes and epoxy in a wood dowel to fill the hole. You could probably skip the dowels and fill the holes with epoxy and wood flour. Just my thoughts. I used about 4 gallons of resin and 2 of hardener on my boat which is smaller then the one you are building.
When I built my Weekender 12 years ago I used Weldwood. If I were to do it again, I'd use epoxy.Â
I've never had a joint fail, but then there are a jillion screws holding the boat together. During the first couple of years I would periodically hear a snapping noise as I moved about the boat. I assumed it was a glue joint letting go. Can't prove it, and I've never seen any evidence of it. The Weldwood is pretty old technology, and I think I'd trust the epoxy more.
Use epoxy. It's stronger, more versatile and easy to work with. You can encapsulate the plywood, apply fiberglass cloth, glue up joints and creat fillets with epoxy. I used Marinepoxy from Bateau.
Dave
There are several advantages to epoxy use. The biggest one, is it's the only stuff you'll need, as it's a coating and an adhesive. It seals the wood, bonds things, makes thing water tight, glues stuff, you'll skin the boat with cloth with it, etc., etc., etc. The best part about epoxy is, it doesn't care how good or bad a woodworker you are. By this I mean most other adhesives require tight, well fitting joints to work, plus lots of clamping pressure during the cure. Epoxy joints can be done with a hatchet (literally), with huge gaps and mis-aligned joints, yet it still bond the pieces together, because it just doesn't care how good or bad a woodworker you are. Try that with any other adhesive.
Excellent point, Paul, about the joint allignment. Titebond III will fail unless the joint is dead on. Same with the polyurethanes like Gorilla glue. With epoxy, all you need is to be in the same zipcode!
Dave
agreed, i did use titebond 3 in a few spots where i knew i had a good joint, but quickly discovered epoxy is the only way to go!
Bob: I laminated my mahogany rafters with Titebond III. I knew the sufaces were smooth and flat, plus that part of the boat will never be in the water (I hope!). Otherwise strictly epoxy.
I like TiteBond III and use it for a lot of stuff. It's about half the price of epoxy (if you buy it by the gallon like I do), but it's uses are never on weather decks or below the LWL. Being a PVA glue, it tends to "creep" under load, so can't be trusted for structural elements that are heavily loaded. This said, I've seen it preform well in loaded situations, but still don't trust it. Also as pointed out, the joints have to be tight and well clamped until full cure (24 hours).
There's really no need for me to comment, but I'll weigh in anyway and join the epoxy team. I used the powdered resin stuff they recommend in the plans. I liked it because it said on the can that the Royal Air Force used the same glue on spruce aircraft structure (before 1950 I'd imagine) and had a picture of a boat steering wheel. Anyway, that's not a good way to choose a glue. I wish I had used epoxy. Oh, the ol' boat is holding together just fine, but I have replaced the glue in the deadwood with epoxy. How did I do that? I waited until all the old powdered-resin crap had crumbled and fallen out, then I drilled holes and injected epoxy with a large syringe. Then I sanded and repainted. You don't want to do that. Use epoxy. The boards in my keel don't move much anymore, but they sure did before the "surgery". I know, Paul, you're cringing right now, but I built the boat before the internet and advice was limited...she's all healed up now.