Disc sander for making things flat and taking material off, scotch brite wheel for deburring/polishing. My scotch-brite grinder (Chinese-made), pedestal mounted, has been in operation for almost 20 years (5 airplanes), still running strong - not with the same wheel of course. My grinder, like most, is dual wheel and I have a different grit wheel on each side.
RV6/2001 built/sold 2005
RV8 Fastback/2008 built/sold 2015
RV4/bought 2019 Flying