Bob, I am a tinsmith and use these tools every day. A grinder has the lowest
speeds you state, and are way to fast for polishing, They also use a much
higher amperage draw than a polisher and will not slow as a polisher will
with pressure. They do not have a variable speed range and will burn
through any gell coat at their rated speeds, read the can a can of compound
from any reputible manufacturer such as 3M or Norton.

Yes, indeed, you ARE busted. My B&D Grinder and several other's I've seen ARE
VARIABLE. Some DO have variable speed. One of the Porter Cable units I used to
use was also variable. Mine goes down to 2500 RPM, though I use higher RPM
during jobs.

http://www.powertoolservices.com/too...on/6154-70.htm

Meanwhile 3M suggests a max RPM of 3000 RPM, but you can safely exceed that by
a good margin. We certainly haven't damaged any hulls using the B&D. Meanwhile
I've never used ANY grinder that didn't slow down quite a bit with a big polish
pad on it and under load.
Stop talking about stuff you don't know about. I actually work on boats every
year.

RB