Cutback and Paint Stripper

[MoskiWoski]

Hey everyone. I ran into some cutback after popping up some old tiles. I put a little paint thinner down to see if it would remove it, and now I read that the paint thinner was a bad idea. It's a concrete slab, I'll be using FlexBond thinset for ceramic tile. My question is, now that I already put the stripper down, what should I use to make sure there is no residual thinner left?? Soap/Water/Scrub/Rinse??? I hear from these forums that tile doesn't like to stick to concrete that's been hit with thinner.

Oh, and if it matters, the thinner said 100 percent Mineral Spirits.

Thanks for any advise.

[John Bridge]

Welcome aboard, Casey. The recommended approach is to grind the surface off.

[MoskiWoski]

That sounds like a lot of work. Haha. Here's the deal, this is a 3ft x 4ft entryway. The wife asked me if I could tile it since we got a couple boxes of tile from her parents for free. My response was, "Of course, but I'll have to buy a tile saw" (the perfect excuse to go buy something). Anyway, the spot that I hit with thinner is only about 12"x12". Are you saying I have to grind the entire surface or just the area I use the thinner?? My thought was, hit it with trisodium phosphate, hand sand it with 50 grit sandpaper, wipe it clean, lay the tile. If I tell my wife I have to grind the surface and full her livingroom with concrete dust, she'll probably file for divorce. Haha.

Is it worth a try?? Be a pioneer? Worst case, tile comes up and I get to cut more tile with my brand new saw!! Or are you saying, grinding the entire surface is my only hope? I've heard of success with going over cutback with a quality modified thinset. Is this a vicious rumor??

I bought FlexBond, but is Mapei Ultraflex 3 a better choice?

[Davestone]

I would just take a claw hammer to the small spot and chip it a little to get a bond.Use the better thinset and you should be fine,yes a good thinset will stick to the cutback.

[cx]

Welcome, Casey.

If you read the Technical Data Sheet for the bonding mortars that say they can be used over cutback adhesive, you'll find they all want the cutback scraped off to the point of being no more than a shadow or stain on your floor.

Even then some of us would recommend mechanical scarification of the surface.

My opinion; worth price charged.

[MoskiWoski]

Hey everyone, thank you very much for the help and advise. I ended up doing some cleaning, scraping, chipping, scraping, cleaning, scraping, and cleaning. Haha. I laid the first 4 tiles of the pattern and figured I'd let them setup over night to give me an idea of how well this will hold. I won't be prying them or anything tomorrow, but I'll know if they adhered. Also, I can use them to push against so my spacers will fit nice and snug.

Again, thanks for the advise everyone. It's very appreciated.