My bathroom had 12" square vinyl tile squares which I chipped off. There is some residue of adhesive left on the concrete. Do I need to try to remove it? The floor scraper I have is not working. Will a solvent help? I am laying large ceramic tile with thinset.
I have successfully used orange oil to soften the adhesive holding vinyl squares. I used it undiluted in just enough quantity to soften the adhesive. Then I scraped up the softened adhesive with a floor scraper frequently scraping off the floor scraper with a 3 or 4" putty knife into a trash can.
I then went over it again with more orange oil wiping with paper towels. Finally I used an electric floor cleaner and mopped. The concrete was still glazed and the tile installer used some kind of floor grinder to roughen the floor. I was not present for this; I was out of town. (The serious professional installation specifications for ceramic tile state that fresh concrete is not to be finished with a metal trowel prior to ceramic tile installation.)
Another way to get a porous top, is to etch the concrete. There is an acid etching solution you can spray on and mop off. Its best outdoors since it gives off fumes, but a few fans to exhaust the room and you should be good. Check for this at a hardware store. I have used muriatic acid etch for many things, patio, sidewalk, driveway, even to stabilize hot tub ph.
Goo Gone goes through this stuff like butter. Just make sure you read and follow all the safety instructions.