ᐅ How to Remove Tar Patina from a Granite Ledge?

Hi,
I might try using a stainless steel cone brush for the angle grinder. It will be tough work, but maybe still better than using and inhaling liters of solvent.

Best regards,

Andreas

So sanding is out of the question. I can’t get into the rough texture with the sandpaper at all.

Solvents don’t seem to help either. Only a slight visible effect.

I tried using a wire brush attachment for the angle grinder. It doesn’t work. It does lighten the surface a bit, but it just drags the dark residue across the surrounding area.

I also tried using a flame from a Bunsen burner. The effect is that some spots chip off thinly and look like new in those areas, but for most of the surface, nothing happens. Too much gas consumption for too little result.

My next approach would be an electric or pneumatic chisel. I already ordered one for the Bosch hammer, but I suspect the cheap €20 chisels from Amazon won’t hold up on granite (even though they claim to be suitable). I’ll give it a try. Maybe there will be some effect, and then I can buy a better chisel. According to the specifications, even chisels from well-known brands like Bosch are too soft for granite. The datasheets say they are only intended for concrete and tiles.

Are there any proper chisels available from stonemasonry suppliers? Maybe someone here knows something.

Try visiting a cemetery—gravestones are made of granite—and ask the stonemason about cleaning agents and possibly chisel manufacturers. Have you ever tried using a steam cleaner?

tadeus321 schrieb:

I tried using the flame from the Bunsen burner.

How about using a roofing torch? No pressure regulator and full power. It could burn everything away. But it might use up a few gas cylinders.