On Sunday, 27 January 2019 18:33:30 UTC, wrote:
I bought a house with a nice outdoor, flat stone tiled walk way.
Unfortunately the tiler/installer was "quite sloppy" in a few areas.
There many of the tiles now have a thin, but annoyingly Noticeble
coating "film" of concrete grout on the top.

I have tried coarse steel wool, with limited (slow) improvement. Is
there a better/ recommended way, to remove that concrete film? I
would really like all tiles to be fully visible, no film.

HCl is the usual solution. It does attack some stone. Sometimes you can just wet the grout for a while then scrub it off with a plastic scourer wad.


NT