i still use mine but its on outside surfaces and with carefull masking if the components are just being R&R'd
shove towel balls in the exhaust ports, clean rust off iron exhaust flanges, gussy it up, that kinda bs...
maybe on a wp gasket for aquick repair job, the problem is that while your grinding away that stubborn piece of gasket, those discs are grinding away alot of the aluminum/material on either side.
besides, a little practice with a razor blade and a cheap holder and youll wonder why the **** you ever used roloc discs.
my green/yellow plastic bristle discs are probably close to 15 years old now....dont use em much unless im completly rebuilding something and can clean thouroughly with my several buckets/bins of kerosene and cans of brake cleaner
