Blue Bear® 500MR Bean•e•doo Mastic Remover –Professional Soy-Based Adhesive Remover for Carpet, Tile & Asbestos Mastics – Low-Odor, Non-Toxic, Safe for Schools & Hospitals –1 Quart

Works like magic on old black mastic, starting to dissolve it almost immediately. After an hour the remover had spread a foot or so past where I had applied it. It is very aggressive but has little scent. It cleans up nicely with a small amount of cat litter and a stiff nylon scrub brush. I used a detergent based degreaser in a spray bottle with scrubbing and multiple rinses with water to finish the job. I finally used a light pass with a hand held concrete grinder to get a good bonding surface. It is not as effective at penetrating old vinyl adhesive. It does soften it in thin layers but it will take time and hard scraping to remove it. You definitely will need a proper scraping tool in this case. The “paper” backing of sheet vinyl thirstily soaks up the remover, however, and comes right up with some firm scraping, leaving the thin, brittle coating of adhesive behind for more intense work, as mentioned above.

ADDENDUM: I have since tried using it on larger patches of the yellow mastic. And, at least in my house, the yellow mastic is impervious to Blue Bear. I have a metal floor scraper, and it's brutal trying to get this stuff up, even after soaking it in BB for 4 hours. The Black, it did really well. Even when it needed a few passes, you could see it dissolving and melting a little more each time. But this yellow, it's not even fazed by it. Like spilling water on it. I am going to do some research online to see if anyone has tips. But otherwise, my dream of concrete flooring is done, because I'm not going back to that toxic fuming stuff that I was trying before. That was not anything I ever want in my house again. And I'm not going to grind 1/2 the house with a grinder. :( I have both black and yellow mastic all over my concrete floors after I pulled up linoleum and cheap tiles. I tried a super toxic produce in the kitchen. It definitely got up a lot of the black mastic, but it was horrible with fumes, even with windows and doors open. Blue bear has a smell to it, but nothing that is a problem. I probably should be using a bucket of this stuff, but wanted to test out a small amount before buying a larger tub of it. The bottle came with a sprayer, and so I just sprayed it on the glue. Then I worked it in with a stiff bristle brush and let it sit for a few hours. Then I used a floor scraper on it. Then I put some Dawn in a bucket with water and scrubbed the floor. Then used a sponge and some rags to dry it up. Since it's a soy product, I just washed the tools up after. It's messy--the bucket has a lot of staining from the mastic glue, but I guess that's expected. Still beats toxic mess. I haven't used enough to need a cat liter clean up yet. But may try that later. It got through the mastic and I now see concrete. It still has patches that are tenacious, but I'm going to be buying the big bucket, and I'm betting that will take care of these tough patches. I would say it works as well as the really toxic strippers, but is a lot easier to work with because it isn't so toxic and hard to breathe. Just be ready to get messy.

Very messy when trying to remove Black mastic. Works best on very smooth surfaces.

This did the trick! We had removed old tile from terrazzo floor but was left with ridges from old, nasty Mastic which would not come up even with floor scrapers applied with hammers! BlueBear 500MR to the rescue - one application, let it sit a short while and we were able to sweep up the old Mastic like saw dust, wash the floor and Voila! - floor clean and ready for beautiful new tile. BlueBear 500MR was non toxic and did not stink up my house with VOCs, which my family and dogs very much appreciated.

I used this to remove old carpet adhesive from some concrete steps. It's very nose friendly and did not stink up the house. On the horizontal surfaces most adhesive would scrape up after a single 12-24 hr soak. A few thicker areas needed a second treatment. On the vertical risers it drained away before it had time to work. I found a workaround by thickening it with a cornstarch paste and then covering with plastic wrap cover for 24 hours. Most vertical surfaces needed 2 treatments but hey I'm still on my first bottle and super happy with results!

I was amazed that this did dissolve the glue on the concrete left by peel and stick tiles and it had a nice smell and was harmless to my skin, BUT cleaning up the liquified glue was impossible..I got covered in glue and after scraping, scrubbing and cursing it is still very sticky. Might work on wood or outside where it could be power washed but in a laundry room ...well I gave up and called a floor company to lay new vinyl..so yes it works, but beware the mess.

I have been remodeling a 1971 home. Under the carpets and other flooring I found loose vinyl tiles and **black floors**. I have ordered several gallons of this stuff by now doing a new area of the house every 6 months or so. The product smells like windex and vegetable oil. It has a slightly thinner consistancy than vegetable oil but washes off easier. Read the intructions, have none plastic or sacrifical cleaning tools on hand, and garbage can near by. Spread it on, let it sit, and use an garage oil absorber (easier to manage) or clay cat litter (has more scrubbing potential but gets heavy quick). Then wash the floor with some dawn dish soap.

Why did you pick this product vs others?: I was hoping this product would work but it didn't. I have a 50-year-old brick fireplace with thick beige glue adhered to it in places. This would not dissolve. We have no idea what the glue is so may not be the fault of this product, just chose the wrong one. Wish I could return it. Thought this product might dissolve it. Big waste of money.