: I never sand to a higher grit than 220 when it'll be coated with
: epoxy. You want a surface that the epoxy will easily bond to,
: one too smooth isn't the ideal.

: Bill H.

I used to use up to 220 but started using 400 and it worked well for me. I use 600 on balsa because it is so soft. No problems with adhering- it soaks up epoxy like a sponge! I have always wanted to do a weight test- taking one board foot of different woods, coat them each with epoxy, and weigh them. I bet the softer woods would gain more weight than the hardwoods. I'm going to start playing around with Paulownia because it's lightweight but not as absorbent as Balsa. I theorize that it would absorb less resin and end up close to the weight of balsa when it's all said and done.