ᐅ Removing the primer from tiles

Hello everyone,

we have a few stains from the primer (potassium water glass) on the tiles. They cannot be removed with a scraper. Is there any product that works? I have already tried almost all cleaners. Is paint stripper an option?

I would be very thankful for any help!

Best regards

I am very interested in this question as well. During the renovation, I wasn’t careful and primer got onto the window glass and the window sills. So far, it hasn’t come off with anything.

Recently, I tried to clean an old spray bottle that was clogged with dried primer. I soaked everything in water... after some time (overnight), it became somewhat rubbery and could be scrubbed off. So the idea is: Maybe you can stick a damp kitchen towel/paper towel to the window overnight, and the material will soften and can be rubbed off.

...that won’t work. Waterglass/silicic acid forms a crystalline bond with mineral substrates (silicification). It becomes one with the substrate. I use this for wall paintings with mineral pigments on mineral substrates. If you accidentally mix too much, it hardens by the next day because crystal formation has already started. Silicification takes 2-3 weeks to complete in summer weather.

You have to accept that; it won’t come off afterwards.

Many primers are acrylic-based, which are easier to remove. It’s not enjoyable either, and if the substrate was porous, you won’t be able to reach everything. Acrylic can be broken down with acetone; I’ve even obtained pure acetone from the pharmacy. Acrylic is not fully waterproof; it absorbs a small amount of water, becomes milky, and loses its strength while still wet.

Best regards
Gabriele