Using a 1500 grit paper, sanding for 5 seconds takes off my top coat. Each time I do it I get sent back to the original plastic. I'm using as minimal a pressure as I can to actually get any contact between surfaces. Is it the paint (elmers paint pen and testors model masters both seem to do this)? Is it the fact that I'm going in lines parallel to the viewing angle (should I be doing circles or something?)? Well, any insight is helpful. Thanks. This can be a frustrating hobby sometimes, but having the boards helps.