What do you use to polish natural stone tiles?

[hdv]

I am in the process of buying a holiday cottage. The building is structurally fine, but needs a lot of LTC to get it up to current standards. In one of the bathrooms some nitwits have written all kinds of texts with crayon on the wall. These are made of natural stone tiles. Not sure exactly what type of stone it is. I have tried to remove the "graffiti" with several solvents, but without success.

During all this I noticed that the surface of the stones isn't flat and would be hard to clean. Not what you want in a bathroom (especially when it comes to the walls in the shower). So, I am thinking of polishing all the walls and kill two birds with one stone: no more weird texts on the wall and walls that will be easier to clean.

What tools would you use for this? A polishing machine with diamond pads comes to mind.

I really would like to not have to resort to wet polishing.

Any suggestions on materials, tools, grids, or alternative approaches would be much appreciated, as I haven't done this before.

 

[Duckler]

That is an interesting problem. Have you tried:
Heat?
Acetone?
Can you hand color the tiles with crayon (or similar) to get an acceptable look?
Maybe hire an artist to do some imitation cave paintings (like Lascaux in France, or that place in Spain). Extinct animals would be my first choice.
Pythagorean theorem written out by some zebras?

 

[hdv]

Well, the problem sadly has become moot by now. The seller didn't stick to the agreement we made, so I had to call the deal off. Too bad, because I really liked that cottage.

As far as the "graffiti" is concerned: I tried all kinds of solvents. I just had to be careful because these hand-cut stone tiles contain a lot of lime and thus can be damaged quite easily. The other thing was that I had to be careful with oily stuff, because that would penetrate into the tiles and create an ugly dark blotch on the tiles you probably wouldn't get out anymore. Sadly nothing worked. I had to resort to using an abrasive in a small test to get that nasty stuff off. Might in part be due to it being on those tiles for about 6 years.

Ah, well. It is not my problem anymore. I hope the next potential buyer figures something out, because that house isn't getting any better and needs maintenance somewhat urgently.

 

[Packard]

Marble, which is relatively soft, sands pretty easily with 400 to 1200 grit paper.  If the marking is on the surface only, that should take care of it.

But marble will absorb color through and through.  I used cut down marble tile to make coasters. I used one for a heat shield for an approximately 3-1/2” diameter candle that was tinted blue.  By the time the candle was fully melted away, not only was the surface of the tile blue, but also the blue saturated through to the other side of the tile.  I knew that wine would stain marble.  I did not know that the dye in candles would leach out and do the same.

If you ever need to clean stone, sanding will work, but it will leave you with a satin finish unless you go to 2400 grit or higher. 

Note:  I threw the blue-tinted mable coaster away.

 

[Cheese]

Well, the problem sadly has become moot by now. The seller didn't stick to the agreement we made, so I had to call the deal off. Too bad, because I really liked that cottage.

Sorry for the bad news... [sad] ...like Packard mentioned, I'd have started with some 240-280 grit paper and see how that works. I've sanded soapstone with 280 or 320 Granat and that works fine for small projects, the paper just doesn't last long.

 

[hdv]

Yeah, I was thinking of sanding as well. What I was wondering about though, was whether I should use a sander or a polisher in the case of soft stone. I was also a little bit afraid of the effect on the machine that the stone dust would have. Moreover I wasn't sure if plain aluminium abrasives would be up to the task, or that it would have been better to opt for a diamond-coated abrasive.

[member=74278]Packard[/member] : I think that exactly is what happened in this case. Just not all the way through. Judging from my testing I think the colour has penetrated about 2 to 3 mm into the surface of the tiles. That would have meant removing about 3 mm from the tiles. Not something you'd like to do every day. But as these tiles were really soft, I think it would have been quite doable.

 

[hdv]

The saddest thing about all this is that even the local real estate agent doesn't want to do business with the seller anymore. And over there you have only 1 or 2 assigned agents per district. So, it will be very hard for the owner to sell that house now. What a waste of a really nice piece of real estate. Sure, it needs some serious TLC. But it has a lot of potential. I was really looking forward to getting that place up to current standards. Now it will probably just rot away. What a shame...  [crying] [crying] [crying]