small voids in otherwise nicely sanded epoxy surfaces

Wondering if you fine folks have a recommendation for filling small voids/low spots in an otherwise smoothly epoxied and sanded surface prior to varnish?
As an example, I've now done 2 to 3 coats of epoxy on my daggerboard.  Post sanding, it looks and feels really good and smooth, but there are a few tiny dimples where an air bubble or epoxy void created a low spot during drying.  I don't want to keep epoxying the thing unnecessarily until those spots finally fill in.  I also tried putting little "dollops" of epoxy over each spot and going back and hand sanding them down, but results were mixed as sanding them tends to compromise the surrounding area unnecessarily.
Is this where people reach for some kind of fairing compound?  Does fairing compound need to be covered in yet another final coat of epoxy after sanding?  What's the trick here?

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RE: small voids in otherwise nicely sanded epoxy surfaces

Since you're varnishing instead of painting, fairing compounds are a no-no.

There's nothing else to do but to keep applying epoxy and sanding until the surface is a smooth as you want it (or until you decide hell with it, daggerboards are either in the well or underwater, who's going to see them?).

Use lots of very thin layers instead of a few thick ones, sand with #220 and try putting the epoxy mostly in thin layers over just the low spots, not in dollops.

Good luck,



RE: small voids in otherwise nicely sanded epoxy surfaces

to build on what laszlo is saying, when i get down to my 'final' epoxy coat after sanding and when there is only small divots like you mention, i apply the epoxy with a spreader which helps ensure the epoxy goes almost exclusively to a divot or low spot and allows for a very thin application.....  then carefully final sand with 220 on a random orbital sander at low to medium speed or hand sand with a sanding block. 

my fill coats are all done with a roller ....but this puts down relatively thick coats of epoxy that are hard to control for a final smooth surface.


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