On Sep 18, 10:09*am, Davej wrote:
Went to Home Depot yesterday and see they have two sanders for rent.
One is a belt sander and the other is a large orbital. Both are
intended for floors. I just need to take the varnish off an old floor.
Is the big orbital the best tool for this? The room is 15x20ft. Any
idea how long this will take me or suggestions on the grit to begin
with? Thanks.

Usually the main floor is sanded with NEITHER of the two types of
sanders you mentioned. Main areas are usually sanded with a DRUM
sander available at dedicated rental centers (not HD). But this will
only get you within a few inches of corners and walls, for that you
have to switch to a hand-held disk sander on casters, these are made
for taking down those last few inches along the walls and have side/
floor casters that roll along the crotch. The corners are done by
hand with a chiesel then a pad sander, etc. As for hand-held belt
sanders, they might be handy on stairs but usually they are useless.

The large disk (buffer style) sander you saw is for your final
smoothing or between coat buffing or to just clean up the wear patina
on an old floor that you want to recoat but not restain or fully
restore.

Drum sanders take practice and a special technique to use wihthout
gouging or causing waves and they draw a lot of current so you'll need
a 20 amp or better outlet. One mistake, and you are up ****s creek.
You also have to strap yourself onto a drum sander to not have it go
through the house wall should it get away.

For just a refinish, where you dont care about getting back down to
bare wood, the buffer orbital, going through 2 or 3 grades of
sandpaper may be good enough.

BUT if you want to stain or you want to totally restore the woods
natural color by total finish removal, you will have to drum sand
through 3 grades of paper taking off about 1/16 inch of surface in
total.