A splash of vinegar or another acidic spill on polished marble, and soon there is a dull ring or patch that won’t wipe off. That usually isn’t a stain. It is etching: acid reacting with the calcite in marble, travertine and limestone and dulling the polish. The good news is that light etching can usually be polished out at home, by hand, with the right powder and a couple of microfibre cloths.
The fingernail test
Run a fingertip or fingernail over the mark. If it feels smooth, it is a light etch and you can fix it by hand with MB-11. If it feels rough, the etch is deeper and needs diamond pads on a hand machine first.
Fixing a light etch or water ring by hand
MB-11 is a polishing powder from MB Stone Care, made for spot polishing water rings and etch marks out of polished, light-coloured marble, travertine and other calcite-based stone. You only need about 1/8 teaspoon per mark, and a 100 g tub treats about 20 marks the size of a 10p coin.
- Put on gloves and test on a small, hidden area first.
- Put about 1/8 teaspoon of MB-11 directly on the mark and mist it with water.
- Rub firmly with a folded microfibre cloth: circles first, then fast straight strokes.
- Spray with Cleaner No.2 and wipe the residue away.
- Buff dry with a second, clean microfibre cloth. Repeat if needed.
Video: MB-11® demonstration by MB Stone Care, the makers of MB-11. In the video they clean up with their own MB-15 cleaner; we use TileMaster Cleaner No.2.
For every step in detail, see our step-by-step guide.
What about deeper etch marks?
If the mark feels rough, MB-11 alone won’t shift it. Use Flexi HD 6″ diamond pads on a hand machine such as a Flex or DeWalt polisher, or any orbital sander, with a suitable hook-and-loop backing pad. Work from 400 through 800 and 1500 to 3000 grit, keeping the surface damp, then finish by hand with MB-11. The pads can’t be used by hand.
Which kit is right for you?
- MB-11 Marble Etch & Water Ring Kit: MB-11, 2 microfibre cloths and Cleaner No.2 spray. For smooth, light marks, by hand.
- MB-11 Deep Etch Repair Kit with Flexi Diamond Pads: everything above plus 400, 800, 1500 and 3000 grit Flexi pads. For rough marks. Hand machine and backing pad not included.
- MB-11 Marble Etch Repair & Seal Kit: the hand kit plus a third cloth and All in One Water Based Sealer 250ml, to seal against everyday oil- and water-based stains after the repair.
Will sealing stop it happening again?
No, and it is worth being clear about that. Nothing you can apply yourself stops acid etching on marble. A sealer helps against everyday staining, but it won’t stop acids etching the surface. For permanent protection against etching, our sister company AntiEtch applies MORE AntiEtch®, “a UV-cured clear coating for marble and natural stone”, professionally on site. It is a premium service rather than something you can do yourself. See antietch.co.uk.
In the meantime, blot acidic spills straight away, avoid vinegar and acidic cleaners on marble, and clean with pH-neutral Cleaner No.2.
Stay safe
Wear gloves, and safety glasses to protect your eyes, when using MB-11. Use it in a well-ventilated area, avoid contact with eyes and skin, don’t ingest it, and keep it away from children and pets. Always read the labels and the MB-11 SDS and Cleaner No.2 SDS before you start.