Sam, I've got a feeling that the edger that I rented at HD was less than
ideal, because it had the sanding surface at a slight angle to the
floor, so that only the front edge would cut. I tried to adjust the
feet and couldn't move them. Should the disk have been parallel to the
floor?

When mine was in the shop one time getting new bearings and gears, I had
to rent one from HD. It was a nice machine, and it worked just as you
mentioned. If you run it FLAT (this is hard work we're talking about
here) it works fine. It's possible that with your lack of experience it
just wasn't as you had imagined. You go through LOTS and LOTS of discs.
You might have to change discs every few feet (like 2 feet) on gummy
finishes.

I was too chicken to use the drum sander AFTER the trowelable filler,
but looking back I can see it would have been a hell of a lot quicker
than the pad sander!

After the wood filler, I do an 80 grit sand with the drum sander, and
then use a slow speed buffer with a red pad and a screen (100, 80, 120,
whatever I have lots of) to close the grain before sealing.

Did you use one of those silly looking "random orbit" type square
machines I've seen? I laugh every time I see one of those. I couldn't
imagine those being effective. I've never used one, so maybe I'm the
silly one. But, they don't look very effective. And, I could see how it
would be a lot of work with that thing NOT drum sanding after the filler.

--
please remove @com.com and change att and dott to @ and .

Thanks, Sam (trying to minimize spam)