Hello Gentlemen,
I'm in the process of removing an existing hardwood (glued down on 3/4 Plywood) before reinstalling 3/4 solid oak. Surprisingly, it came up extremely easy. However, I have been scrapping and sanding the dried glue and I am not sure how far I should go. Currently, I have it fairly flat, all the high ridges (trowwel marks) are essentially gone and all that is left is a thin spotty coating. I am now at the point where the sand paper on the sander just gums up (glue melting). Since I will be laying roofing paper and nailing the new floor in, does anyone see problems with going ahead with the amount of glue left on the floor as l described.
Referencing this sight during this project has been a huge help.

Thanks in advance,
MJKAST

If all the adhesive ridges are gone, the subfloor is flat to industry standards and there are no lumps or bumps of adhesive (and I do mean zero), then you are good to go. Roll out your felt and start laying some flooring (assumming it has been acclimated properly)