gluing to gel coat

I retro-fitted a flipover rudder on my fiberglass kayak (Dagger Sitka). To get the rudder park (that V thing) to fit I had to raise it up with a piece of solid plastic. I used epoxy the first time, and that version is at the bottom of a lake. I used Gorilla glue the second time, and that version fortunately broke at home. I can probably screw or rivet this back, but does anyone have any suggestions for a bomb-proof adhesive?


Use some resin that is the same or at least as compatible with that used in your boat.



I would bolt it
The rudder park is subjected to impact loads (that KLUNK when the blade comes over center)and to shearing loads (when tou push on the pedals while the blade is parked). That is a tough application for any adhesive.

Better to buy longer bolts that will sandwich your spacer between the V-block and the deck.


If epoxy didn’t hold…
…you either didn’t prep the surface properly, you clamped it too hard and squeezed all the glue out or you used really crappy epoxy. Epoxy is the adhesive of choice for structural bonding to gelcoat. Clean the gelcoat surface with lacquer thinner, sand it lightly to give the surface some “tooth” and bond your block to the gelcoat with epoxy thickened with silica, microballoons or chopped fiberglass, clamped lightly. Prep your plastic block the same way.

Have you ever waxed your boat?

Did the wax have silicone in it? (If you used car wax, the answer is yes.)

Nothing will stick until you get the silicone off. Auto body shops have silicone remover. If you went to one with your boat and explained that you want to glue something here, I’m sure you could get a rag-full to clean the area.

5-min epoxy by Loctite from Lowes

– Last Updated: Jul-11-07 8:32 PM EST –

I used for my rudder rest (wood to varnish) with no problem. Tape off the area for the piece with masking tape. Sand both surfaces. The surface of your boat is likely curved. That may be your problem. Stick a piece of sandpaper on the boat surface and sand the bottom of your rudder park to creat the same curvature for better bonding.

That Loctite 5 minute epoxy
makes a great addition to an emergency repair kit too.

Thanks for all of the responses. Here’s some more information:

The gel coat has never been waxed and I did sand the surface before gluing.

I have Yakima pedals with a positive lock, so I don’t push against the V when the rudder is up.

I agree that flipping the rudder is probably the culprit in loosening it.

I’ve constructed it this way. I fashioned an approximately 1" piece of solid plastic (I don’t know what kind) as a spacer between the V piece and the boat. I shaved it on both sides to fit the curve of the boat and of the V piece. I screwed the V piece onto the plastic after I glued the plastic to the boat The screws aren’t long enough to go through the hull, but I can probably find some that will. They have to be stainless steel, as I paddle mostly in salt water. Machine screws and nuts would work if I had 4’ long arms to reach back and attach them. It’s an 18’ kayak.

I think I’ll try epoxy again and longer screws. I’m not sure how much purchase the screws will have in the fiberglass, but perhaps the combination will be strong enough.

If your 1" plastic spacer is polyethylene or polypropylene, any glue is not likely to hold. Try delrin (acetal) or wood (mahogany or teak).

Call Dagger. They should be able to help.You will have to sand the spot that you are going glue the part to. Vaughn Fulton

A Tip on Reaching…
I found this by accident.

If you have a large enough hatch, hang the boat upside down and enter the hatch from below. Seems if you can get your shoulder into the hatch your reach will be greatly extended.

3M 5200. About as permanent as it gets. Clean the area well. Tape off the are where you want the adhesive.(it’s messy). Glue the piece down. Pull the tape BEFORE it sets up.

I have bent crowbars trying to remove things glued on with 5200.