JEM Watercraft

Well Ijust received my plans for the Okwata 15-26, and i'm off to get some plywood to start cutting out the parts. Thankfully I have this forum and a friend who has built Jem's Wadefish, and I started building my own wade fish years ago before our daughter came along and I had to re distribute funds. Now my daughter is almost 3 and as soon as this is done we will be on the lake having a blast.

My first question for everyone has to do with the bulkheads. I plan to install the two optional bulkheads front and rear, but I have heard that it's not a good idea to epoxy and glass them in because the boat will expand and contract with the temp, and cause the joints to crack. What do you guys think.

I've yet to hear of a sealed wood-epoxy-fiberglass chamber bursting because of pressure.

However, it's smart not to temp what possibly could happen. I suggest at least a small inspection hatch in the bulkhead(s) itself if you don't want to cut into the deck. They can be installed into the bulkhead before you install them into the hull.

Thanks Matt. I wasn't worried about bursting, I will be putting a flush hatch in the bow and a small hatch in the back. I was wondering if expansion from hot and cold would cause the hull to crack away from the bulkheads. for example if the hull expanded and ended up larger than the bulkhead. I don't think it will be a problem but just wondering.

If your using the plastic access panels just drill a very small hole in it, say a 1/16th of an inch. Thats what I did on my paddle board. Its big enough that air can get in and out of the chamber and small enough that very little water if any could get in.

Thanks, I will be cutting a flush mount hatch in the bow and probably cutting the rear hatch in the bulkhead. Still not sure on the back hatch, I may install a plastic hatch on the rear deck, I still have a lot of time to think about it.

How else would you install them? More bulkheads = stronger, not weaker.

thanks goanywhere from what I heard, some kayaks have them siliconed in, but after some thinking, I believe that is because they are installing plastic or foam bulkheads in plastic or fiberglass kayaks. Silicone is probably the easiest adhesive to use on those boats for a waterproof seal. I havent seen any complaints on the forums so i will just follow the directions and epoxy them in.

I siliconed my first cedar stripper's bulkheads not due to fear of bursting but because I didn't want a vertical hard point that would cause shearing of the strips if I hit a boulder just fore or aft of that point. I left a gap on the bottom at the joint and filled it with silicone so there would be give at that point. I had once read a book which recommended this. Personally, I think it was unnecessary. I did not do that with any subsequent builds. In my Okwata, I glued the bulkheads into the hull. I never plan on running any serious whitewater and I can't say I have ever paddled fast enough where hitting a rock would break through the hull. If I do whitewater, I will use a nice flexible plastic whitewater boat with no keel.

-Craig

Yes, the main reason is that silicone doesn't adhere to epoxy very well, and would deteriorate in a few months or so, and you definitely want to coat all surfaces with epoxy to seal the plywood. Epoxy will adhere stronger than anything else, is extremely strong, and will last a lifetime if applied correctly. And it has enough flexibility to cope with any normal flexing and heat fluctuations.

Cheers.

I installed the bulkheads on my first with silicone, and will do the same with the current one. Nothing to do with expansion, they had hatches within the bulkheads. I did it with silicone in case for whatever reason I might have wanted or needed to remove or otherwise adjust them. The joint is well protected from sunlight and painted over. Three years on it shows no signs of breakdown at all. A stanley knife or similar and I could remove it in an hour. Just gives me an option.
Cheers John.