14' Gamefisher leaking rivets

[islandscope]

I recently acquired a 14’ sears gamefisher jon boat that was in pretty good shape overall, but it looked like the original transom was rotting out and it very slowly leaked, though it wasn’t an issue when I was on the water. Anyways, the first thing I did was replace the transom. For that I glued and fastened together two pieces of 1/2” plywood, then sealed the whole thing with west system, but didn’t fiberglass it. I adhered it to the aluminum with loctite 8x and used stainless steel bolts with 5200 instead of rivets. Seems pretty solid and I also put on new aluminum handles and a motor clamp board on the stern, which bolt through the transom.



My main concern is the leaks. I knew of one problematic rivet on the floor and took a friend’s advice to just go over it with aluminum brazing rods. After that I kind of went to town and did all the rivets on the floor, except the ones I couldn’t access under the seats-those ones I did from the underside of the boat instead. So the I filled the boat with water to test it, and pretty much all the rivets I did from the top(the floor of the boat) were leaking. I think the water was creeping between the rib and the hull. The ones I hit from the bottom were pretty much all water tight. Now I’m realizing I probably took the wrong initial approach and I am unsure how to finish my leak-fix job.

It now seems I should’ve just tried to rebuck the rivets before anything. Another solution if that didn’t work would have been to replace the rivets. Rebucking seems off the table, I imagine I could probably grind off my brazing job and replace the rivets, but I will reserve that for a last ditch effort. I think the answer is some combination of brazing, 5200, and a gluvit or steelflex type sealant? I’m leaning towards brazing the rivets from the bottom and maybe applying a sealant inside for insurance, what do others think? Should I start with one over the other? Should I 5200 the seams between the ribs and hull?

 

[DaleH]

Yes, in retrospect I believe bucking rivets should always be the 1st try.

With that said, if not used in saltwater I'd use West Systems G-Flex 650 from the inside as it is a permanent but flexible epoxy. A kit with enough to do all your rivets 2-3X over is $22. Only downfall for that or ANY epoxy product is that it needs to be painted to protect it from UV. I have some great write-ups in PDF from with pictures from West here in the files, search under my name.

 

[islandscope]

Thanks for weighing in. Here on the Vineyard we have a number of coastal salt/brackish ponds which is primarily where the boat goes, so would that rule out the g-flex you recommended? Is it possible to apply 5200 to problem areas before I seal the whole thing, or would that negate how the sealant works?

 

[DaleH]

Well 5200 itself can corrode tin if the tin isn't primed beforehand. The neat trick on the G-Flex 650 is the tin can be warmed so the goop weeps into holes you can't even see. I think if it were mine, I'd turn it over, scrub areas to be gooped with white vinegar and a copper scrub brush, then rinse well. Would use the G-F 650 product as per the various PDFs I've posted, or go to the West Systems site, and would then paint the bottom or where rivets were covered. Could even do from bother sides to ensure sealing them. That G-F is significantly more viscous (thin, penetrating) than 5200 ever hopes to be.

I see people Steel-Flex the entire hull, even panels where there's no rivets, as the co$t of that product is not inexpensive and while yes it is good, I wonder why they just don't consider the G-F 650 on the rivets option ...