gelcoat thinning

[pursuit2460]

When using styrene to thin gealcoat do I have to add more mekp to make up for the styrene. Example if I pour 1 quart of gelcoat and mix the mekp for 1 quart and then add styrene do I have to add more mekp to the mix.<br />Thanks

 

[Chief101]

Re: gelcoat thinning

It's not a real critical mix, but I usually catalyze to the volume, yes would be the answer.

 

[ondarvr]

Re: gelcoat thinning

How much styrene do you plan to add?<br /> <br />It is recommended that no styrene be added to gel coat, but in some situations gel coat does need to be reduced to spray through a siphon gun. Styrene will cross link with polysters and is in most formulas, but if too much styrene is added it can cause problems. Styrene has very little strength, so it weakens the resin and/or gel coat and may make it brittle leading to cracking, plus it has terrible UV restisance and will cause yellowing, it will also increase the amount of shrinkage while curing.<br /><br /> A 3 to 5% addition of styrene should not be a problem, but much more than that and you can start to degrade the gel coat.<br /><br />You can buy products formulated for reducing gel coat, while most of them do contain styrene, there are other things in them also.<br /><br />Add 1.5 to 2% catalyst to the entire mix.

 

[pursuit2460]

Re: gelcoat thinning

What can i buy to thin it out besides styrene. I am planing on spraying it with a spray gun and need it to be asthin as possible without affecting the gelcoat.

 

[ondarvr]

Re: gelcoat thinning

The same place that you buy the gel coat should have products to thin it down. Ask for a patch aid type product. There should many places around Miami that sell fiberglass and related products. If you can't find a place to get it, let me know, I may be able to get the name of a place that has it.