Jan 23, 2026 - 07:01 AM
We’ve provided several answers to questions related to Strippers & Thinners , see some other helpful Q&A related to this product.
Question: What is mastic?
Answer: Mastic is another name for adhesive.
Question: We have old wallpaper to remove. Just spoke with Joel and he recommended this product. I now see that some older reviews mention that the product is not very viscous and that it's difficult to use on vertical surfaces. Is that still true for the latest, current version of the product? If the product is painted on the walls, with regular paint brush or roller, will it stay on long enough to do the job?
Answer: No. It's for removing strong adhesives only from concrete surfaces. I'm also guessing the wallpaper is on drywall and the mastic will ruin the drywall as well as any wood trim. We sell nothing to remove wallpaper.
Question: will this mastic remover harm the underlay of vinyl plank flooring I'm planning to install once mastic is removed?
Answer: FranMar 500MR Mastic Remover can only be used on concrete subfloors. It cannot be used on wood subfloors. Follow the directions on the PDF "Specs and Installation" to make sure all residue is cleaned up before installing your new floor. https://www.greenbuildingsupply.com/c...
Question: Is blue bear mr 500 and degreaser 700 safe for my drains?
Answer: Their products are, but the finish your removing with it may not be.
Question: Will it remove the adhesive used to our down outdoor carpet and how much is needed for 500 sq.ft. area. I haven't found anything that works unless you apply (Goo Gone) and scrape and repeat over and over. I'm looking for a remover that works.??
Answer: Adhesives vary so much that it's best for you to first order a small sample online to test in an area to see if it works for your particular kind. As for coverage, that is stated toward the bottom of the product page under Specs, " Coverage---1-Gallon = 100-125 SF - if no trowel marks150-175 SF - for vinyl and latex mastic or black asbestos mastic if professionally trowelled (i.e. there are clear trowel marks)5-Gallon = 500-625 SF - if no trowel marks5-Gallon = 750-875 SF - for vinyl and latex mastic or black asbestos mastic if professionally trowelled (i.e. there are clear trowel marks) ".
Question: Does this chemical remove mastic on indoor wood floors?
Answer: Franmar Blue Bear 500MR Mastic Remover effectively removes difficult mastics from concrete subfloors. Not wood.
Question: Will I be able to install porcelain tile over a concrete floor treated with 500MR?
Answer: Thoroughly clean off all the oil residue several times with a degreaser and you should not have any adhesion problems.
Question: Can I paint my concrete floor with the SafeCoat paint after cleaning it with the Blue Bear 500?
Answer: Yes. Follow the directions and thoroughly clean (we recommend you use FranMar's 700DG Degreaser to aid in that after project clean up), and rinse your floor afterword. Let dry, then you can prime and paint.
Question: Is this safe to use if my wife is pregnant?
Answer: We'd recommend not having your wife be the one to do the application of the product as most times bodies are extra sensitive during pregnancy, but the product itself is Non-toxic, non-corrosive to skin and contains no hazardous ingredients. It is for everyone, including the chemically sensitive.
Question: After the mastic and franmar is adsorbed by the absorbent, is it possible that any potential asbestos can become friable again?
Answer: The Franmar Mastic Remover will soften the mastic and the two will blend. After mastic has softened, you'll remove with a long handled scraper or squeegee. If needed, you can use an absorbent, such as kitty litter in which case the mastic and mastic remover would amalgamate with the absorbent. See full instructions here: https://www.greenbuildingsupply.com/c...
Question: Will this product work on hardwood floor that has tile laid over top ?
Answer: Most tile is set with thinset mortar. The 500MR is made for removal of mastics but only over concrete subfloors and not hardwood. That's because it requires lots of water for clean up and dumping that much water on your wood floor can be harmful.
Question: I stepped in mastic and tracked it on the pool deck stone. Will this help remove it?
Answer: This mastic remover is made to remove mastic from concrete surfaces (I'm attaching a link below for application instructions). As such I do not know if it would work on your pool deck stone, much depends on the type of stone and if there is anything else the mastic is attached to (grout, mortar, etc. stone finish). The best thing I could advise it to order a test sample size (4oz) and give it a try in an inconspicuous area to see if it will do the job.https://www.greenbuildingsupply.com/c...
Question: does this item aid in removal of existing thinset or mastic?
Answer: This product will remove mastic from a concrete subfloor, it will do nothing for thinset. Here are the application instructions that spell this out in more detail. https://www.greenbuildingsupply.com/c... Thinset (being concrete) you would need to manually scrape.
Question: Can you use your product to remove glue residue from the bottom of a fiberglass boat?
Answer: Maybe. There are so many different types of adhesives, it certainly warrants a test to see if it works. If it does, then it will save lots of time and energy. Be sure to clean it well as it may also remove some of the gelcoat if let on too long.
Question: My tile installer slopped thinset on my new vinyl plank floors. I asked them to clean it up, but they only partially cleaned the floors. There is a lot left that is really hard now. I didn't imagine it was going to be such a hard to remove it. Calling the tile people back is not an option at this point. What do I use that will remove the thinset without damaging the floors?
Answer: Oh gosh. With the disclaimer in place first that we do not sell vinyl floors or thinset, so please take this with a grain of salt. I can tell you that the 500MR Mastic Remover is NOT the product to use for removing thinset from the top of your vinyl floor. Mastic remover was designed to dissolve mastics/glues from subfloor surfaces. I would suggest reaching out to the thinset manufacturer to see what they advise. Failing that, try a google search on how to remove thinset (or concrete, or mortar) from vinyl flooring - I see recommendations for white vinegar soak, and using putty knives to pry up, but as we don't sell vinyl we can't offer official support. Good luck!
