Hi guys, I sprayed about 2 quarts of supposedly waxed factory gel coat right from Formula boats on my 272. Catylized it right at 2% MEKP and did not thin it at all. Sprayed at 68 degrees air temp 64 degrees surface temp. After 55 hrs at 68 degrees The areas I sprayed over the epoxy fairing compound didn't set up at all, surprisingly the thinner areas cured fairly well and the rest of it seems to only be partially cured. None of it is hard enough to sand without loading up the paper. What gives? I feel like I was sold unwaxed gel coat even though I asked multiple times to make sure it was waxed. The can has no markings aside from the batch number and color. I did wipe the area with a cloth dampened with acetone 60 minutes before spraying. Maybe to solvents soaked into the porous fairing compound and off-gassed under the fresh gel? Can I spray PVA over this crap to get it to cure? How about spraying another coat of gel over it with Patch-aid mixed in?
Its not looking like the expoxy areas are going to harden at all. I sprayed gel over another area of fairing compound that sat overnight (12hrs) after being acetone wiped and its not curing either. Any advice will much appreciated, feel free to text or call Steve 774-930-5591

Some epoxys and gel coat do not play well together. It will depend on what specific products were used.

I will let Glass Dave chime in because he knows better , but been there and done that , and told not to do it.

Did a similar polyester gel over a epoxy repair way back on the day.


Scraped it off


Dave is a Rocket Scientist

called Steve direct . . . .cause thats what glassdave does (sometimes lol)

do share!!!

there were temp as well as substrate issues. Steve was having problems of the gel not curing over a West System epoxy repair and in chatting found that he did a final wipe down of the repair with acetone and i suspect that woke up some amine that then inhibited the cure of the polyester gell coat. Its best to wash with just plain water but truth be told i dont much care for mixing products like that, i rarely if ever PE gel over epoxy. I also suggested that he switch to a simple coat of PVA to get final cure.

thanks for ask'in

thanks for telling

Dave can you do a vinyl ester resin repair over a epoxy constructed built boat that Has gelcoat such as some of the epoxy Fountains out there?

I take it the epoxy would be old enough that the blush couldn't be woken up anymore, does the blush affect vinyl ester like the polyester!
I have never worked with vinyl ester but very comfortable with epoxy so always used that for repairs.

But it makes it hard to gelcoat match.

I fixed a 1 by 1 foot hole near the waterline on my buddies 45 foot Lagoon sailing catamaran he poked in it from the tide laying him against the corner of his floating dock.

Luckily he did it in the only part of the boat that I wouldn't have had to saw one of the 3 bathrooms up to get at it, soo he lucked out.

Unbelievably that boat was built with one layer of 1708 on the outside than 1 inch balsa and than one layer 1708 on the inside.

I was very adamant of making the repair look factory outside and inside since it was a 1/2 million dollar boat.

Anyways I wanted to use epoxy for the bond and workability and reduced shrinkage but I needed gel on the outside.

I enlarged the hole 2 by 2 and removed all the coring. Than screwed a piece of starboard to the outside from the inside. Started brushing on layers of gelcoat inside onto the starboard ,followed by by one layer of 1708 with polyester resin , with the patch only catching the edges of the old hull.

Let that kick for about 4 days than did 2 layers 1708 with epoxy than some 3/4 inch balsa and 2 layers of 1708 over that.

Blended perfect inside nice and level and I was confident my repair was twice as strong as original.

I was afraid if the gel repair didn't blend well enough a future surveyor might dig deeper and remove the interior trim panel to find an extensive repair.

The gel I used with no wax just PVA being my belief that the wax creates the haze and yellowing in a white gel.

4 years later you can not find the repair, even when the boat is out of the water.

No charge for my buddy since he never makes me chip for gas when he takes me out sailing.

lol "never makes me chip in of gas while out sailing"


i'll revisit this I a bit, posting from phone at the moment. I have some insights on thin laminate repairs.

Talk about me blowing the Punchline.

That close to Trying to being a Comedian I was.



Like hearing your shop talk and your advice on repairs.