What is gelcoat and is it needed.

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AKCoastie

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May 12, 2008
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I am planning on stripping, filling, and painting the bottom of my boat this winter. Until I started poking around these forums, I was just planning on using automotive primer as the base for my paint. After looking around, I have seen alot of talk about gelcoat. What exactly is the purpose of gelcoast and will primer work fine instead?
 
ondarvr

ondarvr

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Re: What is gelcoat and is it needed.

To answer your question accurately we'll need a little more info on the boat and what exactly you plan to do.

I assume the boat is made from Fiberglass. If it is, then the color coat you see is the gel coat.

Does it have bottom paint, or something else on it now?
If so, then it (bottom paint not gel coat) needs to be removed before painting.

If the hull finish is still the original gel coat, then do not remove it, it only needs to be sanded before painting.
 
JB

JB

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Re: What is gelcoat and is it needed.

Gelcoat is a resin similar to the resin used in the fiberglass, Coastie. It is thickened to a pasty, but usually sprayable, consistency, usually with diotomacious earth (CabOSil is an example) and has coloring in it. It is used to make a smooth, sandable surface on the reinforced fiberglass of the hull.

Many purists prefer to recoat a hull with fresh gelcoat rather than paint, but it would seem a waste if bottom paint would be going over it.
 
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AKCoastie

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Re: What is gelcoat and is it needed.

Yes, it is fiberglass. The bottom is pretty dinged up and will need a fair amount of filler. It looks like someone has already put a crappy second layer of blue paint on it that I was planning on sanding off. I am assuming that gelcoast can be sprayed over primer correct? The only real reason I was planning on using bottom paint was because that is what I came across when I googled painting the hull. I have a couple of years of experience painting cars but none working on boats. Is there a difference in durablility between gelcoat and paint? What about price?
 
ondarvr

ondarvr

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Re: What is gelcoat and is it needed.

The old blue paint does need to come off, bottom paint is only used when a boat will be sitting in the water for long peroids of time to help prevent stuff from growing on the hull. Paint and gel coat are very different products, so no primer is used under gel coat, it would be sprayed directly over the old gel coat after it is sanded and cleaned.

Gel coat may not be what you want to use though, paint is easier and will work fine if this is a trailer boat.
 
A

AKCoastie

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Re: What is gelcoat and is it needed.

ondarvr said:
The old blue paint does need to come off, bottom paint is only used when a boat will be sitting in the water for long peroids of time to help prevent stuff from growing on the hull. Paint and gel coat are very different products, so no primer is used under gel coat, it would be sprayed directly over the old gel coat after it is sanded and cleaned.

Gel coat may not be what you want to use though, paint is easier and will work fine if this is a trailer boat.
Click to expand...

Sounds good. Thanks.
 
Woodnaut

Woodnaut

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Re: What is gelcoat and is it needed.

Coastie, some of the new bottom paints are eco-friendly, but some of the older ones contain a lot of toxins - which is how they inhibit marine growth. Bad news for any living organisms. If you're going to sand off the old paint, you really need to do so with a full respirator/mask and avoid breathing in any of the dust. Safety first. :)
 
A

AKCoastie

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Re: What is gelcoat and is it needed.

Woodnaut said:
Coastie, some of the new bottom paints are eco-friendly, but some of the older ones contain a lot of toxins - which is how they inhibit marine growth. Bad news for any living organisms. If you're going to sand off the old paint, you really need to do so with a full respirator/mask and avoid breathing in any of the dust. Safety first. :)
Click to expand...

Ok. Thanks for the heads up.
 
oops!

oops!

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Re: What is gelcoat and is it needed.

AKCoastie said:
Is there a difference in durablility between gelcoat and paint? What about price?
Click to expand...

heh heh heh.......

gellcoat is crazy tough stuff it can last well over 40 years.....i had to grind off some of my boat.....it burnt a dewalt grinder....the gellcoat is 40 years old and would have lasted another 20.

all fiberglass boats have a gellcoat......look at any new boat.....thats not paint!
 
fuzzeywiggler

fuzzeywiggler

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Re: What is gelcoat and is it needed.

I would go the painting route.

Go on http://fiberglassics.com/ > "Click the Start Here" Button> Click on "Fiber Facts" on the left hand side Read the gelcoat "facts".

It explaines alot.

Fuzzey
 
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