Why did acid cleaning leave my granite tiles spotty?
Estimated Reading Time: 2 MinutesQ. Hi, I recently acid cleaned my granite tiles using a 1:20 hydrochloric acid to water solution. The problem is I didn't wet the tiles first so now the tiles look spotty. Is there any way I can remove the acid from the granite tiles? I am keen to do it soon before it gets too baked in. Thanks for any guidance you can provide.
A. It's a good thing you're addressing this problem quickly. Flush the surface thoroughly with plenty of clean water to dilute and remove any remaining acid. This will neutralize and stop any ongoing reaction. Allow the tiles to air dry.
Acid damage on granite (the spotty areas you mentioned) can't be washed away. Acid damage is chemical damaged to the stone itself, or to the sealer on the stone, not a residue on the surface. Although granite is more acid-resistant than marble, hydrochloric acid is strong enough to attack certain minerals in granite or damage sealers unevenly.
If the stone is acid etched, you will need to hire a professional stone restoration contractor to hone and polish the surface. To find a vetted PRO in your area, visit www.surfacecarepros.com and click on Find a PRO. Your PRO can also determine whether to reseal the granite if the appearance change is from uneven sealer loss. Your PRO may want to do a very light polish or buff before sealing to even things out. They can select and properly apply the most appropriate sealer.
We understand this is a frustrating situation. Many people are told granite is “acid safe.” In general, this is true, but granite is not impervious to damage from very strong acids. Unfortunately, this is not a problem that can be resolved using DIY methods.
For more simple but important granite care instructions, download our free Stone and Tile Care Guide.
ABOUT THE AUTHOR Fred Hueston is the Chief Technical Director at SurfaceCarePROS.com and Director at StoneForensics.com. He is also the author of Stone and Tile Restoration: The Manual, a comprehensive online manual for stone and tile restoration contractors. [Learn more about Fred.]