I’ve got a situation. I’m building a sauna in my basement, and the guy that built the house allowed the room I’m using to be carpeted using carpet glue. A LOT of carpet glue - right on the concrete basement flooring.
There is a lot of then hard-as-hell glue that I’ve removed using a razor scrapper tool and a mild, biodegradeable adhesive remover, but it’s been really hard work. And now I’m left with the thin bit of tenacious glue that is down in the little variances of the concrete surface. I’ve tried some adhesive removers, but most of them are pretty nasty stuff that I either don’t want to handle, or I don’t want to flush down the drain in the floor and out into the septic system.
Is there something I can use that will basically dissolve the remaining thin glue remnants, and then let me neutralize it so that it can be safely flushed down the drain and into the septic tank? I have images of some kind of acid that would just eat the stuff up in 15 minutes, and then I take some other chemical that neutralizes the acid and makes it OK for the septic system.
Anthing powerful enough to dissolve carpet adhesive is going to have to be pretty nasty stuff and is not likely to be good for your septic sytem. Have you tried a floor sander? I don’t know how one would work on concrete, but it might be able to grind off most of the surface glue if it didn’t damage the concrete surface.
As another thought if it’s just a small area in crevices is to use use a power drill and brass wire drill brush or palm style power sanding pad, or if the crevices are very tiny, a Dremel and a Dremel type brass wire brush.
I’m starting to reach the same conclusion - that a sander of some kind is the way to go. A sander would have clogged right away before most of the stuff was removed, but now it may be the best option.
If the remaining glue is hard, smooth, and well-adhered to the floor, why do you want to remove it at all?
Just paint over it, or lay whatever new floor covering you want over it.
There’s a point of diminishing returns on cleaning out the old to make way for the new. You’ll have to decide where that is based on your plans & situation. Just make sure you haven’t crossed over that line.
What are you going to be putting down on the floor?
Depending on that, you may not have to bother removing all the leftover glue at all.
For example, if you are laying tile, as long as the floor is basically smooth, the leftover glue can just be covered with the new glue or grout for the new tile. Same for many wood floors.
Use a heat gun or hair dryer to heat up the glue to soften it and then scrape it off with a razor scraper or stiff putty knife depending on the smoothness of the concrete.
Rent a grinder and attach 24 grit resin fibre discs on a rubber backing pad. The high rotating speed combined with the coarse grit will go a long way before build up on the discs becomes a problem. You’ll need to control for dust though.
If the carpet mastic is pretty buch scraped flat you can always trowel a thin layer of thinset over it then seal it, looks and wears like ordinary concrete. If you are going to tile, just go ahead and tile over it, if its stuck good it wond effect you tile adhesion.