how much sanding of epoxy?

 I've got two good coats of epoxy over the wetted fiberglasss and I have faired and sanded up to 180 grit. Nice and smooth, right? Yes, but there are very small pits (approximately 1/8" diameter) that show through the sanded surface, perhaps distributed at a rate of one pit per four square inches or less. They show up as a speck of glossy surface and they are barely detectable by touch. The pits aren't deep in the sanded surface. I'm concerned that if I sand enough to make them go away I'll sand into the fiberglass, which may show through the final Interlux gloss varnished surface. Do I really need to continue sanding and maybe recoat the exposed 'glass or will the varnish hide a few minor sins nicely?

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RE: how much sanding of epoxy?

it sounds like you are probably ready to varnish.

that said, different folks have different standards.....but i doubt based on what your describing that anybody would notice these minor imperfections.

here would be my suggestion.   varnish a small section and see what you think.  you can pick a 12 inch section of the side of the hull.  if it looks fine, just continue.  if it doesn't, then sand the little section of varnish off and use a skim coat of epoxy to fill in the little indentations.

a skim coat is applied with a squeegee...and does not involve a lot of epoxy.  the squeegee forces it into those final little depressions.  and then after the squeegee coat, it is just a very light sanding and your ready to go.

hope that helps


RE: how much sanding of epoxy?


Depends on the level of finish you're going for. If it's a workboat finish, then as Howard says, you're ready. If it's a museum piece, you're not. 

Personally, I'm somewhere in between. I like to get the pits down to the occasional pinhole-sized, at least. That gives a nice smooth base for any kind of finish. From where you're at now, that would be one more very thin coat of epoxy and one more sanding session with #220, if you choose to go for pinhole or smaller.

Remember, if you can feel them, then you'll be able to see them. On the other hand, unless you're trying to win a prize it won't make a difference. And the boat will float and perform just as well no matter what level of finish you use.

Have fun.




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