I can't comment on your polishing system but I have played with a little
plastic. I've noticed when polishing Lexan that too long of contact will
cause melting in the plastic. The first couple of times I created tiny
bubbles, then some distortion, then a niced clear finish. My advice is
practice until you are happy before doing your "keeper" cube.

"Jack" wrote in message
om...
Hi I have a 3500 RPM grinder and the Beale polishing system for
woodturners from packardwoodworking.com. I am trying to polish a
thick hard plastic (polyurethane) cube. Does anyone think this is not
the correct application ? If this is not the right way, then can
someone tell me why this is not good (ie I will burn it or worse), and
make a suggestion as to how to polish hard polyurethane blocks with
minimal effort?

thank you !

-Jack