How to Cure Non-Waxed Polyester Gelcoat

[ADMPRTR]

Hello:
I accidentally applied non-waxed gel-coat to the underside of a hatch that I recored but three months later it is still tacky. Now I understand that I should have bought waxed resin because the non-waxed version will not cure in air.

What are my options to remove the tackiness, please?

[cabo_sailor]

It's been a while so I'm not 100% sure it will work. You can try spraying it with PVA mold release, basically a liquid paraffin I believe. Just spray it on and hopefully it will cure. I've also heard of people just coating the repair with plastic wrap but I don't know how well that will work for you. As a last resort you might still be able to remove the offending gelcoat with solvent such as acetone and re-do the job.

Hope this works,

Rich

[ADMPRTR]

Thanks Rich. I will try those things. Luckily, it is the underside of the seat that I gelcoated so it is a minor irritant as opposed to a major issue.

Regards,
Andrew

[colemj]

Why not just apply another coat of gelcoat with inhibitor? It should bond to the uninhibited layer, although 3 months is a bit of time.

Mark

[ADMPRTR]

BTW, what is the best alternative to using polyester gelcoat to finish fibreglass work? I am thinking of low wear areas (i.e. lockers).

Options I am aware of are: epoxy paint, boat enamel and polyurethane?

[Pete7]

The surface is tacky because you didn't exclude the air as it set. However, it should be solid underneath. The wax rises to the surface during the cure.

Grind or sand the surface layer off and then apply either another coat with wax or paint it.

Pete

[ADMPRTR]

Originally Posted by colemj

Why not just apply another coat of gelcoat with inhibitor? It should bond to the uninhibited layer, although 3 months is a bit of time.

Mark

Ya, that is an idea. Thanks.

[ADMPRTR]

Originally Posted by Pete7

Grind or sand the surface layer off and then apply either another coat with wax or paint it.

I thought of that but I wasn't sure how well it would sand.

[svholdfast]

Just apply heat, a heat gun works.
Myron

[Pete7]

Originally Posted by ADMPRTR

I thought of that but I wasn't sure how well it would sand.

It will make a horrible sticky mess of any sand paper you use and probably need MEK to wipe down with afterwards. Go easy with MEK, nasty stuff and can soften GRP, but you have nothing to loose at the moment.

Myrons suggestion might be worth a try first though.

Pete

[Jim Cate]

Originally Posted by ADMPRTR

BTW, what is the best alternative to using polyester gelcoat to finish fibreglass work? I am thinking of low wear areas (i.e. lockers).

Options I am aware of are: epoxy paint, boat enamel and polyurethane?

In Oz, and likely elsewhere there is a product called "Flo-Coat" that is good for this application. It seems to simply be pigmented polyester that is thinned out until it flows like paint. Used it when reglassing the bilge in our last boat, and it worked very well... and it is Cheap to boot!

Cheers,

JIm

[donradcliffe]

Originally Posted by Jim Cate

In Oz, and likely elsewhere there is a product called "Flo-Coat" that is good for this application. It seems to simply be pigmented polyester that is thinned out until it flows like paint. Used it when reglassing the bilge in our last boat, and it worked very well... and it is Cheap to boot!

Cheers,

JIm

Polycor is available in the US, and is probably the same stuff as Flo-Coat.

[Maine Sail]

Just wipe the existing surface with Acetone or MEK and mix up some more poly resin, this time with wax, and roll it on. You could do the same with waxed gelcoat. What you have there will not cure as the MEK-P is long gone and the curing has all but stopped. I've done the same a few times and a fresh coat, with wax, fixes it.. Crawl around boats long enough and you'll find plenty of exposed laminating resin that is still tacky, even at 30+ years, that never got coated with finishing resin or gelcoat.