Oh, wow, can I relate to this! We have a home built in 1905 - we have removed sooooo much glued on flooring that we could have built another house with what we've thrown away! Black gooey tar like adhesive was ALL over our kitchen floor after we pulled up over 5 layers of added on flooring. We could not sand the heart pine flooring b'cause it would just gum up and eat the sandpaper - I don't remember how we heard about this - but - We slathered lots of Goop handcleaner on large areas (divided the room 18'x18'into about 6-8 sections for ease in working) then covered the gooped area with a layer of wax paper (Cut-Rite in the little tear off box from the grocery store :o) and let it stand about 1-2 hours. Removed the wax paper and used a large (8-12 inches long) metal or plastic scraper on our hands and knees to scoop up the now mostly loosened and dissolved black sticky tar-like stuff. We slopped it into buckets and dumped it in a hole in the back yard. We then washed each area well and we were able then to lightly sand the floor without gumping up the sandpaper or burning up the sander. It took some time and elbow grease - but the hand cleaner worked wonders - plus, it kept our hands clean. We bought about 15-20 jars of handcleaner (I think at Lowes or Home Depot) to finish the entire job. We had to keep the working areas covered w/wax paper in order to create a mini greenhouse effect to allow the Goop to loosen this tar-like stuff. Try it in a small area and see if it works!!!! Our kitchen floor looks pretty good for almost 100 years old and after being buried under 5 layers of various flooring.