Dura-Kote Gelcoat Surfacing Agent

[expozen]

I'm trying to do some gelcoat. I bought a can of "Dura-Kote Gelcoat Surfacing Agent" from my local boat store. The can has no instructions on it. But it does say "10% surfacing agent" on the front. Which I assume means that it contains 10% wax and 90% solvent.

The can of gelcoat I have says to mix 3% surfacing agent for a topcoat.

So do I mix in 3% Dura-Kote to get 0.3% wax? Or do I mix in 30% Dura-Kote to get 3% wax?

[GordMay]

Greetings and welcome aboard the CF, expozen.

Dura Koat Instructions ➥ http://www.durakote1.com/wp-content/...structions.pdf

➥ http://www.durakote1.com/

[Spot]

My supplier's web page for SA has mixing information:

https://www.expresscomposites.com/s-...ent-liquid-wax

Durakote also had good phone support when I used some of their products a few years ago.

[expozen]

Originally Posted by GordMay

Greetings and welcome aboard the CF, expozen.

Dura Koat Instructions ➥ http://www.durakote1.com/wp-content/...structions.pdf

➥ http://www.durakote1.com/

Unfortunately, nothing in there says anything about mixing surfacing agents.

[expozen]

The last time I tried this I used 3% DruaKote. But the gel oat directions say that if it’s cured correctly it wouldn’t be tacky after an hour. It was still tacky after an hour so I sprayed PVA over the top and let it sit for a day. It seems to be cured after that. I assume I could just omit the surfacing agent all together and use PVA over the topcoat?!

[Spot]

Originally Posted by expozen

The last time I tried this I used 3% DruaKote. But the gel oat directions say that if it’s cured correctly it wouldn’t be tacky after an hour. It was still tacky after an hour so I sprayed PVA over the top and let it sit for a day. It seems to be cured after that. I assume I could just omit the surfacing agent all together and use PVA over the topcoat?!

I have been told that PVA can be used to create the barrier to allow the polyester resin to cure 'hard' (without air inhibition) but I have never done this. I would go to the gel coat manufacturer and ask this question.

The last time I did a wax additive gloss coat, I overworked it with the brush, disturbing the risen wax and creating brush marks and sticky spots on the project. The shop was also a bit cold which did not help. I ended up 'faking' a barrier with wax paper and most of it cured well enough to leave it alone.