Sealing fiberglass bulkheads

I have a Nigel Dennis kayak made of the standard fiberglass layup. The bulkheads are also fiberglass, and they’re starting to leak a little bit. The flat bulkhead is molded with a lip about 1" long, perpendicular to the bulkhead so it can get glassed into the hull and deck.

That lip leaves kind of a rounded edge on one side of the bulkhead, and I thought about sealing it with clear silicone. Any other ideas on what I could or should use?

Repair glassed in bulkheads
I would not use silicone. Just sand to rough up the area and reglass them in. Once you use silicone it will be almost impossible to get off. Do it right the first time.

agree…sound advice…do it right the first time.

best wishes


If they’re already glassed in…
…you may just need to apply another coat of resin over the joints to seal any pinholes. You can use polyester, vinyester or epoxy for this. Clean the area well and sand it lightly for best adhesion.

Sounds similar to QCC
if I understand your description. QCC seals theirs with ITW Plexus adhedive, a two-part material. Check with a marine dealer for something similar. THe problem with silicone is that once used, nothing else will ever stick to the surface.


Thanks for the advice, glad I didn’t go ahead and do it first… I think they use vinylester resin so I’ll probably go that route. It’s a fiberglass bulkhead which is glassed into the glass hull and deck (I think it’s Diolene actually).

Vinylester can be hard to find
You can get epoxy or polyester resin at Home Depot, along with fiberglass tape, mat and cloth. Since you’ll probably be doing some repairs and/or modifications eventually, spending $20 on a quart kit of Everfix epoxy is probably a good way to go.