My first gel coat experience, what went wrong?

[pdqaltair]

Works with epoxy too.

I know the instructions say "65-80F" or something like that, but you can mix the components at ~ 50F and the pot life will double. They will still cure just as well and as quickly, because they warm on contact. Can make wetting out glass tricky, so not great there. Best for big epoxy bonding jobs. I learned it from coating large storage tanks and concrete containment, where products come in 5-gallon lots and it is TOUGH to use them that fast. No good for spraying 2-parts, though.

Really, a hot weather trick, not germane to your difficulty.

[CalebD]

I have only dabbled with Gel coat once and I believe it was the more liquid variety rather then the paste.
The worst things about this product is its smell and pot life are minimal so use a mask and gloves.
Once it cures completely it can be sanded with very, very fine sandpaper to match (or closely match) the surrounding surface.
Getting the colors to match is more of an art then a science.

[scottyt]

if you want to try to match the gel coat it can be done. get a tint kit, then mix a small amount about 1 oz with the tints till you think you are close then add the catalyst . then using a hot dog foam roller roll on a nice coat of it an inch bigger than the repair. once it cures if you are happy with the match sand it out with 600 grit wet. if it does not match mix another small batch and tint slightly different, add the catalyst and roll it on. every time you do this go another inch bigger area. when after a few tries you will get it close enough, sand it out, then polish.

with the evercoat you do need to wipe with a dewaxer before the next coat

also for filler use micro ballons, its much easier to sand it later. you will not need much so a small jug will work. but you dont want it when rolling just filling

[sailingdog]

Yes, you'll need to wipe with a de-waxer for any "finishing" gelcoat resin, which has wax in it and can air cure... since the wax floats to the surface and seals it so it cures properly... leaving the wax on the surface...

Originally Posted by scottyt

if you want to try to match the gel coat it can be done. get a tint kit, then mix a small amount about 1 oz with the tints till you think you are close then add the catalyst . then using a hot dog foam roller roll on a nice coat of it an inch bigger than the repair. once it cures if you are happy with the match sand it out with 600 grit wet. if it does not match mix another small batch and tint slightly different, add the catalyst and roll it on. every time you do this go another inch bigger area. when after a few tries you will get it close enough, sand it out, then polish.

with the evercoat you do need to wipe with a dewaxer before the next coat

also for filler use micro ballons, its much easier to sand it later. you will not need much so a small jug will work. but you dont want it when rolling just filling

[jarcher]

Thanks for the tips everyone. What should I use for a dewaxer? Acetone? Thinner 216? MEK?

So for the nest step I need to dewax, then sand a bit, then use a roller for another coat. Correct?

I'm not worried about matching the color now, as this gel coat is all hidden anyhow.

[sailingdog]

interlux fiberglass prep wash 202 works nicely

[Liquorice]

Nobody said this so I'll chip in!

A handy way to colour match small gel coat jobs is to mix in a clear plastic container. The sort of thing you get when you buy a boat part that's been "packaged" in a hard, clear, plastic wrapping.

Stand the clear container over the gel coat to be matched. Mix the white or clear gel coat with your chosen tint colours until it lookd the same. Then add hardener.

However, it's still going to fade over time in the sun, so, as the man said, it's a bit of an art!

Sam :-)

[Bene505]

Thanks for this post. I ordered 2 (2 ounce) tubes from Spectrum Color. It was about $52 with shipping.

It's worth extra to me to not have to mess around with getting the color right. I'd probably spend more than that considering the wasted gel coat from unsuccessful matching attempts.

Now, do I need to put a UV lamp on the results to get the same fading as the rest of the boat?

Originally Posted by TaylorC

I've never used any of the Evercoat products (and gererally distrust any product that uses a K where it ought to have a C) but I think if you are trying to repair chips in gelcoat that what you need is something more like a gelcoat repair paste that liquid gelcoat.

I've used the gelcoat repair kits from Spectrum Color on my Whaler with some success. Their claim to fame is pre-matched color for a bunch of different production boats. The repair kits have a 2 oz jar of gelcoat thickened into a paste which does a nice job of filling chips where you have some depth.

Gelcoat needs to be protected from air in order to harden correctly and the standard approach is to either add a special 'wax' to the liquid gelcoat or to spray PVA stuff over it... but these kits come with all the right stuff premixed.

Another option is to use white Marine-Tex. Trowel it into the chip and then tape some plastic wrap tightly over it while it hardens. But you may find your boat is not the same white as the Marine-Tex - or even the evercoat gelcoat you are using now. Not all white boats are really white...

Actually, the plastic wrap trick will work with the gelcoat paste also.

What I do is mask off the repair with some very thin tape, fill the chip or gouge and then tape the plastic wrap over the repair and use my finger to try and smooth it out. The plastic wrap gives the repair a smoother finish.

You will end up with a little extra thickness (of the tape you used to mask) and if you are trying to go for perfection you can wet sand with 600, 1200 and then buff and wax to make it even and shiny.

Even if you don't use Spectrum's products, you might have a look at some of their instruction pages