I have a solid gray-black concrete sink from Kvik, in the bathroom, it's surface-treated with some kind of lacquer or similar, very nice when it was new. But now acetone and other chemicals and stuff have dripped onto it, so the surface layer is dissolved and matte in some places. I've tried with soap flakes, as the dealer said to polish with, but no result. Timberex oil, no result, olive oil, cooking oil, hard wax, same thing. Does anyone have any good ideas for a durable surface treatment or should it be replaced with one in porcelain? Thanks for answers.
Have the same problem. Apparently, you should only use natural stone oil. No cleaning agents can be used. Will probably replace that sink with a porcelain one eventually.