Sanding Skamol board

[Jeri D]

I thought I would find something easier then the fiberboard to use in my kiln, but how in the world do you sand it smooth without gouging it. it seems with every little swipe (using fine sandpaper) it picks up its own grit and marks it even more What am I doing wrong?
I am kilnwashing it to fill in grooves, but then how do you remove kilnwash without marring it up again.

Inquiring frustrated minds want to know

jeri