Last week, my tile guy installed sandstone (very porous) in my bathroom. I have since learned he never worked with this stone before. I now note mortar stains along the edges of most tiles, and can actually feel the the mortar buildup where the stains are (rough feeling). The limited info I can find re: this stone indicates it is very sensitive to harsh chemicals. So, how do I remove the mortar without affecting the stone??? Another compounding issue, I used onyx to accent the sandstone and that is extremely sensitive...Please help!
There are a couple of options:
Use mechanical alternatives to chemicals. These methods include power washing or special power tools for cleaning mortar lines in brick. These tools can be rented at most home improvement or hardware stores.
1. Mix together 1 part muriatic acid and 4 parts water as a chemical option. Make sure that you pour the acid into the water.
2. Apply diluted hydrochloric acid as another chemical option. Wet the mortar completely with water but do not oversaturate. Use a dry nylon brush across the stained area first and then add the hydrochloric acid solution.
Good luck!How to remove dried old mortar off used brick?