I have used white baking flour mixed with sanding dust to thicken epoxy to be used as a filler. It sands as easily as wood flour, keeps the epoxy nice and light and once the boat is glassed it seems to blend in nicely.

Stay away from using Cabosil w/epoxy for filler because it is very hard when it cures. It is great for fillets though.

: Recently I mixed some wood flour with diluted Elmer's wood glue to fill
: staple holes and that went ok except the surrounding cedar soaked up the
: liguid residue and is going to take a lot of sanding to get rid of the
: staining. At first I thought this approach looked good, now that it is dry
: and I am doing some sanding, maybe I screwed up!!! Have read about
: something called cabosil what is it and will it work better as I have lots
: more staple holes and cracks and gaps to fill. What works best for this on
: western red and white cedar???