Acid Damage

The photographs below are from a client in Putney, and show what will happen to a Polished Marble tabletop if you try and clean it with Viakal. Marble is made from calcium and magnesium carbonate which makes it acid sensitive, Viakal on the other hand is an acid cleaner blended from Formic and Citric acids resulting in a pH level of 2.2. This product uses the acid to dissolve the calcium and magnesium deposits in Limescale.

To be fair to Viakal the label does state not to use it on natural stone, but who reads the label, certainly my clients cleaner hadn’t. The result was the acid had etched the lovely, polished Marble surface and it appeared to be ruined.

I was happy to re-assure my client that the etching could be removed, however, to do this the table would need to be burnished with a set of diamond pads of different grades. This process cuts into the stone with a coarse pad to remove the etching and then slowly builds back the polished appearance using finer grades of pad. The table was very heavy however so the work would need to be done on-site.

Polishing a Marble Tabletop

Due to the weight of the stone table, it couldn’t really be moved so my first job was to relocate nearby furniture, roll up the rug and cover everything in blankets and a drop cloth. The last thing I wanted was any other possessions getting splashed during the burnishing process.

When polishing Marble floor tiles, I would normally use large 17-inch diamond pads fitted to a rotary floor buffer, however that simply wouldn’t work on a table, so I ordered a set of 6-inch burnishing pads from Tile Doctor instead. These smaller pads fit nicely on a hand-held buffer that would be perfect for this situation.

The burnishing process involves working through the pads in sequence. I started with the coarse 100, 200 and then 400-grit pads applied with a little water, these coarse pads were able to remove the etching and ingrained dirt. The table was rinsed down and then the 800-grit medium pad was applied which is the first step in the polishing process. Again, this pad is applied with water to lubricate, and the table was rinsed down afterwards.

The process was repeated with the 1500-grit fine pad and then the 3000-grit very fine pad to bring up a really nice shine to the Marble table, I should mention the last pad is applied dry with only a tiny amount of water sprayed onto the surface.

Sealing a Marble Table

The last step was to seal the stone to protect it going forward. I used Tile Doctor X-Tra Seal for this, it’s an oil-based impregnator and I figured the oil in the sealer would mask any marks that I wouldn’t be able to remove, however I actually ended up removing all the etching so the sealer just gave the stone a really nice colour and gloss.

My customer was very pleased with the work and said that the table looked better than it ever had before. NB. For the aftercare cleaning of a polished Marble coffee table like this I recommend the use of Tile Doctor Stone Patina Spray which has been especially formulated for the regular cleaning of stone worktops.

 

Professional Restoration of a Marble Tabletop in South London