Will acetone remove granite sealer with scratches in it? Is it safe for granite?

Q. We have hair line scratches in our granite vanity countertop that looks like it has just scratched the seal and not the stone. Will acetone remove the sealer so we can verify, fix, and reseal the area? Also what acetone would be recommended for granite?

A. As you noted, what often looks like scratches on the stone are really just marks in the sealer. Before attempting any fixes, it’s important to determine whether the scratches are superficial or if there is actually damage on the surface of the granite. 

To check, start with a visual and touch inspection. Sealer scratches usually appear lighter or hazy and feel smooth, while real stone scratches are deeper and can be felt with your fingernail. A simple water test can help, too. Put a few drops of water on the scratched area. If water beads evenly over the area, the sealer is intact. If it becomes absorbed into or darkens the stone, the sealer is breached. You can also gently wipe a small section with acetone or alcohol. If the mark lightens or disappears, it’s likely only in the sealer; if it stays, it may be in the granite itself.

You can purchase acetone in the paint department at a home supply store. Regarding selection, one bottle of acetone will be the same as another bottle, regardless of which brand you choose. Acetone is a powerful solvent, and it should not hurt the granite. Make sure the area is well-ventilated and follow the manufacturer's safety precautions. Test in an inconspicuous area first, just in case it produces undesirable results, such as unevenness or dullness.

Isopropyl alcohol is a great alternative to acetone for your purposes. It is less aggressive but still effective at dissolving sealers.

For scratches on the stone itself, honing and polishing will be necessary to restore the finish. A stone restoration contractor with the knowledge, experience, and specialized tools to refinish granite can perform this service for you. To find a vetted PRO in your area, visit www.surfacecarepros.com and click on Find a PRO.

After your sealer is removed, new sealer should be reapplied. NOTE: proper sealing is more than just spreading a liquid on the surface. Granite sealers protect the stone from stains, moisture, and damage, but applying them correctly requires skill and knowledge about the type of granite and sealer. A PRO will ensure the surface is fully clean and dry, apply the right amount of sealer evenly, and allow it to penetrate and cure properly. Improper application—too much, too little, or uneven coverage—can leave areas unprotected, cause a hazy or sticky finish, or even damage the stone. 

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.]