Thinned Gelcoat with Xylene!

[Klink Sanford]

I mistakenly mixed Xylene to thin no wax gelcoat then realized it, so I didn't use it. I put hardener in it to throw it away or use it as a paper weight ($ ouch!). This morning it was hard as a rock, and not sticky, thought I used no wax additive. It dried better than the new gelcoat that I actually applied. (All brush applied, no spraying.)

Could I have used it?

 

[kapnD]

You’ve answered your own question.
Now leave your paperweight out in the sun for a few years and report back !

 

[Klink Sanford]

Now leave your paperweight out in the sun for a few years and report back !

Will do sir.

I'll put it on the silver roof of the barn, so it gets no shade breaks.

 

[ondarvr]

If was in a container the mass generates good deal heat, so the cure is typically far better than if you spread it in a thin film on the surface of something.

Also, adding "thinners" to gel coat in more than a very small amount tends to do more harm than good.

What thinner did you plan to add?

 

[Klink Sanford]

What thinner did you plan to add?

I thought it was Styrene. I didn't add much Xylene, like 1 oz to the 27oz of gelcoat. I had acetone right in front of me, I could've added that had I realized I was putting in Xylene..

 

[ondarvr]

Don't use styrene, it yellows terrible when exposed to the sun, but one ounce of anything isn't going to cause much of an issue, the xylene was probably fine. At 1 oz it won't have much effect on the sprayability either.

Acetone in small amounts is OK, but people don't frequently get the expected result, so they add more. A small amounts of Acetone will do a great job at lowering the viscosity in the spray gun, but as soon as it comes out of the gun much of the acetone is evaporates, so the leveling isn't improved much, this results in more being added, which ends up messing with the chemistry more you may want.

 

[Klink Sanford]

Ok, thank you very much for your advice.

 

[mrdebian]

@ondarvr what is the recommended way of thinner gelcoat if you have to do it?

 

[gonzo]

The best for spraying or brushing is Duratec clear additive.
https://www.amazon.com/904-001-Dura...ocphy=9018833&hvtargid=pla-570351315505&psc=1

 

[mrdebian]

@gonzo the problem with Duratec is that is impossible to find it where I leave, not even in the whole country. A German company that I found with stock doesn't ship it abroad.