Gelcoat (sanding)

[Saeed]

I've got a 33' boat, have removed the paint, sanded the gelcoat with 220 and 320 grit, but can't sand any more as gelcoat is too thin, should I apply a layer of gelcoat ( primer first) and carry on sanding then apply gelcoat, if so how many layers of gelcoat should i apply - then sanding what grade of paper should i start with 60 to 1200 or 220 to 1200.

Sanding - its killing my time - doing it manually, any tips on mechanical means of sanding.

Currently doing wet sanding, is this best or dry sanding.

[Corpus Skipper]

If you insist on a gelcoat finish, prepare to sand!!! If that doesn't sound like much fun (it ain't) then I suggest a good polyurethane paint job. Much easier, way less labor, CHEAPER, and indistinguishable from gelcoat unless you examine it with a microscope (o.k., a tape line here and there might give it away). If you MUST gelcoat, spray (best), roll, or brush another coat on, and sand with 220 using a DA (Dual Action) sander on the flat parts only (you'll strike through on corners, etc... Then wet sand manually with 400, then 600, then buff with coarse compound, then fine compound, I like to finish off with rouge, then wax, 4 to 6 coats for ultimate shine. Two passes with polyurethane nets nearly the same results in one day rather than the two weeks to finish gelcoat. Good luck!

[jammer]

I agree with Craig, but if you must gel coat it, Thin the gel with a product called: Duratec Clear Additive. It allows the gel to flow rather nicely on a spray gun with a 2mm tip and leaves a surface like and enamel job, tack free. Either way it's a big job!
Good luck

Dave

[Buckle]

Saeed - A problem with rubbing any form of gel coat with sand paper is that by rubbing, you are introducing porosity into the gel coat. In doing so, your oasmosis protection is serverly reduced.

A good tip so reduce porosity (especially if you rubbing a dark hull) is to hit it finely with something like 400/500 grit. Therefore as soon as you hit porosity, you can quickly jump up the grades with minimal scaring.

As you have already hit it hard with grades lower the 400 etc, your not really going to get an excellent porosity free finish. You an epoxy paint for a good finish.