Gelcoat vs. Paint?

[skatebros]

ok, so i am looking into reinforcing under the bond line on my 01 superjet. is there a gel coat on there that needs to be ground off first? or not? i am confused here. too many different answers.

 

[Mile9c1]

The white stuff is paint.

 

[Mile9c1]

You know what's strange, I've never seen paint peel on a Yamaha, but I see it all the time on the Kawasaki's. Hmmm :sneaky:

 

[simopimo]

Skatebros, just paint it after you're done. You don't need to grind the gelcoat off, but you should prep it before painting.

Actually, if you're going to reinforce fibreglass, you really should get it back to raw fibreglass rather than repairing over the top of the gelcoat.

So yes, get it back to raw before putting any more fibreglass on top.

 

[SUPERJET-113]

Gelcoat is generally only used at time of construction on fibreglass because it won't cure when exposed to air. It's sprayed into the mould first, then the fibreglass is sprayed over the top using a chopper gun. Flowcoat is a derivative of gelcoat which does cure when exposed to air - it's really good to use on the hull or in the engine bay because it's thick like gelcoat but is easier to apply.

I would hate to try and paint a ski using gelcoat. What a nightmare.

Gel coat will dry exposed to air, it will just take basically 24 hours to cure. When I do gel coat repair, I use mold release and brush or spray it on right after it starts to set up. Here in Havasu it takes about 2 hours in this heat to cure that way. Then I wet sand and buff...:biggthumpup:
If you did a whole ski in gel coat would be a nightmare like you say. You would be wet sanding a buffing for hours. Not to mention all the hard places to get where you would have to do it by hand.. :frown:

I've read about that FLowcoat get coat. Sounds like that would make things a bit easier if you had a large area to do. Fortunately I know to stay away from big crap jobs like that. I make way more money doing little jobs..

 

[simopimo]

Superjet-113, you're right. I should have qualified what I said - what I meant by gelcoat failing to cure when exposed to air was that it wouldn't cure without assistance, whether by some form of mould release or something similar (or plastic wrap etc).

Like you say, imagine sanding it back when on a whole ski? Geez... I'd pay someone to do that rather than doing it myself.

 

[ArtMaybee]

As far as gelcoat curing there are waxed and unwaxed.
Waxed gelcoat is made to cure when exposed to air. The wax rises to the surface and seals it so that it can cure.

Then you have unwaxed that won't fully cure without a long cure time, extra heat or saran wrap or whatever.

Just remember to sand a waxed gelcoat before adding any additional layers if needed or the next layer won't stick.

 

[Idok]

Superjet-113, you're right. I should have qualified what I said - what I meant by gelcoat failing to cure when exposed to air was that it wouldn't cure without assistance, whether by some form of mould release or something similar (or plastic wrap etc).

Like you say, imagine sanding it back when on a whole ski? Geez... I'd pay someone to do that rather than doing it myself.

butti's black and white ski took forever to get the sanding done...2 guys, 3-4 nights and probably 5-6 hours per night :bigeyes: