It the only way i do it. I use 1200 but don't think it will make much difference. Once the mr.S had really harden, buff it with a 4000 micro mesh cloth and it will get a nice super smooth surface. If the micro mesh is not available use a coffee filter. It is best to use the Polly S Plastic prep, the pink stuff. Is is anti-static to reduce the chance of dust in the Alclad.