Boat Repair/Bonding Epoxy to Fiberglass- Question

(I posted this in the "Materials" forum also. I hope this does not cause confusion.)

Greetings,

Thanks to everyone for your helpfulness. I've read a lot. There is a lot of experience here!

Epoxy resin is highly recommended for saturating wood before installation, but I understand that epoxy and poly resin do not mix. How do you bond the 2 substances together?

Here is my situation:
In my boat, one of the storage compartments was made from painted plywood. This box hung from the bottom of the inner shell of the boat, and was connected by glass tape and resin. This box has rotted out.

I want to fabricate a new epoxy-saturated plywood box, using glue and stitch methods. But HOW should I connect the epoxied box to the underside of the existing shell? This is a structural connection, and will have to withstand approximately 150 lbs of gear bouncing around at any given time.

Or...Would you recommend other methods to fix this situation?

All suggestions are appreciated. Thanks in advance for the assistance!

 

Follow up, several years later...

I used a very coarse, 60-grit sandpaper on a right angle grinder to put a lot of "teeth" on the original surface, then used epoxy and 1.5 ounce glass biaxial tape x 4", a fillet, and then a 2" wide layer of tape. Followed with topside paint, and the results were strong and beautiful. That storage locker continues to be strong and in good shape.

Epoxy adheres well to the fiberglass, if you get through the gelcoat, and have a nice, rough texture before you start.

-TH

 

Wow, 5 year old post. Still nice that you report back. Well done.

Indeed epoxy will adhere without any problem to polyester based laminates, as long as they are sanded and clean. Indeed remove the gelcoat or topcoat, as that is not as strong as the laminate below that.

If you have pictures, why not share them!

 

Herman,
I normally would, but the computer that had those pictures died, and I just re-discovered this site, and wanted to do follow-ups on the work you guys helped me with.

But the end result was very nice. It looked like the smooth white inside of a fish box. The corner fillets were smooth, and I was proud of the work.

Not much to see, unless you knew what it had looked like before!

-TH