Colorant

[TMeyer]

I have a customer that has a portion of their sanded grout/ceramic kitchen floor either painted or a poss. colorant. There are large areas that have the natural grout without any topicals. Can one use a colorant over the existing areas that are colored and if not how do you remove it?.

[John Bridge]

Hi T,

Please wait for the restoration pros to answer, but it sounds as though it could be a topical like lacquer or acrylic. I think you'd want to strip this off before proceeding with something new. No telling how well the old stuff is bonded.

[kemguru]

Hi T

It depends on what was used. Most topical coatings can be removed with TYW Heavy Duty Cleaner & Stripper. Actual grout colorants may require a Methylene Chloride-based paint stripper. No fun, to say the least, but it does work.

I like Sunnyside Glue & Adhesive Remover (Methylene Chloride), from True Value Hardware.
Apply to dry surface
Let dwell at least 10 minutes, but no more than 20 (or so)
Pour a little water on it
Scrub with a stiff nylon brush
A little more water
Scrub a bit more
Extract with a wet-vac
Repeat if necessary

A good acid wash after stripping will make it look real nice and open the pores up, so it’s ready for resealing.

I don’t recommend going over existing topical coatings. Your new seal job will only be as good as the old sealers bond. It can flake off.