Poultices for removing marble stains are fairly available and many hardware stores and even Home Depot sell kits that make stain removal easier. Sometimes a DIY solution is all you need, that said, it’s our business to restore marble and natural stone professionally, so when in doubt always call a stone care professional. Knowing when to try a DIY poultice will save you time and aggravation, and a little knowledge will go a long way to that end.
Know the difference between a Stain and Etching
Stains or discolorations on marble or natural stones can take two different forms.
1) If the discoloration is darker than the stone then it is a stain.
2) If the discoloration in lighter than the stone, then this is surface damage which has nothing to do with the absorbency rate of the stone. This is called etching and is most often caused when an acidic product or substance, comes into contact with the stone.
Etching differs from staining. Staining is when a product such as coffee, wine, ink, oil or dirt is spilled on the stone. Another common stain is rust.
The best way to remove a stain is to use a poultice. A poultice is a combination of a very absorbent medium mixed with a chemical that is selected based upon what type of stain you are trying to remove. The concept is to “reabsorb” the stain out of the stone. The chemical will attack the stain, the agent will pull them both out together. The most common ingredients in a poultice are baby powder and hydrogen peroxide (the clear kind available at a beauty supply store, the drug store type is too weak). Sometimes in the case of ink, denatured alcohol is more effective. And with oily stains, acetone is the best. It is available at any hardware store. NEVER use nail polish remover!