Primer for Gelcoat?

[Breynolds]

I just repaired my transom and glassed in the top. I am going to spray gel coat over the repair area. My question is do I need to apply primer before the gel coat and if so what is a good primer for this application.

 

[Woodonglass]

Re: Primer for Gelcoat?

No Primer! Light Sanding. GOOD cleaning with Xylene (Watch those vapors) Ready to Paint This might be helpful..http://www.boatdesign.net/forums/open-discussion/spraying-gelcoat-over-gelcoat-6328.html

Good Luck

 

[Robert4Winns]

Re: Primer for Gelcoat?

You would only need a primer if you did the repair using epoxy, in which case you would need a special type of primer. If you used poly you don't need a primer.

 

[Breynolds]

Re: Primer for Gelcoat?

I did the repair with fiberglass mat and resin. So I can spray gel coat right on top?

 

[Bondo]

Re: Primer for Gelcoat?

I did the repair with fiberglass mat and resin. So I can spray gel coat right on top?

Ayuh,... As already noted,... Only if it was Polyester Resin...

 

[basspirate]

Re: Primer for Gelcoat?

make sure you read the back of the gelcoat to see if you need a vapor barrier like pva (2 step gelcoat) for a full cure. trust me if a vapor barrier is needed and you dont use one the gelcoat will NEVER dry. I like the way the way 2 step finishes much more than the 1 step. the 2 step finishes exactly like the original gelcoat where the 1 step balls up and gets gummy when sanded. a company called fiberglast sells the gelcoat and pva much cheaper than any marine supply. evercoats pva costs about $16 per pint which does not go very far where as a gallon from fiberglast cost me $22 and i swear it was the exact same stuff.

 

[Breynolds]

Re: Primer for Gelcoat?

Thanks for the input guys. Bond-o I realized how stupid my question was right after I posted it. I was thinking you were talking about some other kind of material all together. Sorry for the brain freeze. Thanks again everybody.

 

[Breynolds]

Re: Primer for Gelcoat?

One more question. How cold can I spray this stuff. I read on 1 post not to below 65 degrees. Is that a definite must? What happens to it in colder temps say around 50?

 

[vegasphotoman]

Re: Primer for Gelcoat?

at 50 it might not stick well and plus it will layout poorly...plus you'll be lucky if it shoots through the gun at such a cold temp...

 

[ondarvr]

Re: Primer for Gelcoat?

It won't cure or spray well at lower temps and depending on where you bought the gel coat they should also sell surface wax so it will cure correctly and not be tacky, its easier to use than PVA.

If you can't fine wax or PVA you can wipe the surface down with acetone to remove the sticky layer before sanding.

 

[Breynolds]

Re: Primer for Gelcoat?

I guess I will wait till I can get some decent temperatures before I spray it. I don't want to mess it up. The styrene that they sent me has wax mixed in it so I should be good there.