finishing before epoxy/glass

[mathewfarrell]

Most of my work is timber surfboards—usually western red cedar or paulownia, and occasionally other random timbers

I finish these with epoxy and usually bamboo fabric, occasionally fibreglass for special cases.

I'm used to sanding the timber to at least 220 before hitting it with epoxy. Anything coarser and the swirl marks from the RO sander can be visible under the glass.

My question is two-fold—do you think I need to sand these timbers to get epoxy to bond, or would a planed surface bond just as well? they're both pretty porous timbers, but I wonder if they become too slick when planed?

Also, for raw timber, a planed finish will show up depth of grain and knots like nothing else. Would a planed finish under epoxy (or any other finish, I guess) look superior, or do you loose this advantage when you saturate it (ie, would a sanded finish look just as good once the resin's on)?

[RufflyRustic]

What does the expoxy packing say? I would have thought any finer than 220 would be too smooth for applying epoxy??

cheers
Wendy

[mathewfarrell]

G'day Wendy

Unfortunately the package doesn't really say anything. I suspect you're right about smoother than 220, but haven't experimented to find out...the simplest way really is to try it.
I wonder if it's a bit of a hypothetical question anyway, since I probably won't be able to get away with just planing. I'll probably have to hide a lack of skill behind the Randy sander.