I don’t feel any residue or film or anything but nearly positive it’s either super glue or gorilla glue. I tried rubbing alcohol, vinegar, and a generic cleaner but no change. [img]https://cimg8.ibsrv.net/gimg/www.doityourselft.com-vbulletin/2000x1504/15038267_2754_4d92_be73_615cd65aaa3b_5794be3cafba99ef7240b6339537c25713382083.jpeg[/img] [img]https://cimg2.ibsrv.net/gimg/www.doityourselft.com-vbulletin/2000x1504/4afc6dce_a4f5_42c1_b36a_2e03f02be00c_2e9c162e85b31a67f804ee088be7098c6a81b270.jpeg[/img] [img]https://cimg5.ibsrv.net/gimg/www.doityourselft.com-vbulletin/2000x1504/a0428ae4_0ebd_4b5a_ab8b_5435636b5bca_6485f5a83f7309b4b06e5ad581e111ec79260bb2.jpeg[/img]

We have three rooms of 1960's solid white oak flooring currently clear finished [unstained]. We're going to buy more white oak for two more rooms. Then, we will stain all five rooms a medium/darkish brown. The current floors are #1 common. It would be nice to save money with #2 common for the new flooring, but don't want an obvious cheaper looking/lower quality appearing floor. One vendor said that stained we won't see a difference between #1 common and #2 common. Looking for opinions. With the color range we are looking at staining, will the difference in grade be apparent? Also, how much do grades vary between manufacturers, meaning do some pass-off lower grade pieces as higher grade more than others? Thanks guys!