Hello, after several passes with 24G abrasive sleeve on a drum sander the hardwood floor is mostly but not completely stripped of the old varnish. Some patches still retain traces of the finish. I was wondering if this is something to expect? I thought that the combination of a drum sander and a 24G sleeve would make one extra careful not to damage hardwood floor as opposed to applying extra force to the drum. Or should I have been pushing the handle down all the time, which would be exausting?

Your symptom is usually associated with cupped or bowed flooring. Sometimes you need to use a curved scraper to remove the remaining varnish.

Your symptom is usually associated with cupped or bowed flooring. Sometimes you need to use a curved scraper to remove the remaining varnish.

Thanks. Unfortunately, the answer is I have been given a broken drum sander at the Home Depot rental shop. The drum was out of alignment and the sander itself has long passed its prime. Talked to the guy who rented it to me and got a replacement for one day free. Will be sanding for another day. Free of charge. Fun!