marble/slate bar counter top

Dear Jane:

Let's start by setting the record straight: those water spots are not stains at all and they were certainly not generated by water. They are etchings (marks of corrosion) that are the consequence of spills of drinks. Every drink, including most sodas, are acidic in nature and corrode most marbles and many a slate. In other words, you're not dealing with stains, but actual surface damages.

Now, what can you do about that?

If the etching is not too severe and or too extensive, if your top is made of marble you may want to try our Marble Repair Kit. If not, only a reputable stone restoration contractor will be able to refinish your top to its pristine conditions by lightly grinding the surface of the stone first (honing), and then polishing it with an appropriated polishing powder for marble.

If it is slate instead, there are two possibilities: 1. The slate is ground and flat (like a chalk-board). In such case you will have to remove the etchings with sandpaper, either by hand or with an orbital sander (do NOT use a belt-sander). You will start with 120 grit and then go up on the grits to 800 or more (if you can find more). That is the best shine that you can hope for with slate. Finish the job with the application of a good quality stone color-enhancer like MB-6 following the directions printed on the bottle.   2. The slate has a natural-cleft finish (kind of rippled, not flat and smooth). In such case, there's nothing than you can do other than applying a good quality stone color-enhancer like MB-6, not to actually repair the etchings (which would be technically impossible), but to hide them from site.

And BTW, just in case you're wondering, whether it's marble or slate (or at least that particular slate), there's nothing that you can apply to it that could even begin to prevent those etch marks. It's the wrong stone in the wrong place- end of the debate. L    

Ciao and good luck,

Mauri zio Bertoli