Cleaning up sandblasting media

quicksandfarmer · Jul 23, 2018

Hi --

My house has a foundation of large blocks of cut granite. A few months ago I had the interior sandblasted using a "dustless blasting" process (water mixed with the air). It looks great, they took off 150 years of accumulated grime. However, there is a thin layer of blast media on the stone, particularly in the cracks and crevices, that I cannot get off. I've tried vacuuming and washing with TSP and water, but there is a stubborn residue that won't come off.

The blast media is 40/70 crushed glass.

Any suggestions?

Thanks.

oosik · Jul 23, 2018

Definitely. Call the company that did the sandblasting and see what they recommend.

So the "sandblasting media" is a mix of water, glass and air. I would bet you are going to have to use some mechanical means of removing the imbedded media - such as some type of wire brush.

quicksandfarmer · Jul 23, 2018

oosik said:
Definitely. Call the company that did the sandblasting and see what they recommend.

I plan to do that.

oosik said:
So the "sandblasting media" is a mix of water, glass and air.

It's been a few months so it's really just glass and air at this point. Probably 99% of it vacuums up. There is a stubborn film that seems to resist and persist. If you've ever dealt with drywall dust you'll know what I mean, you wash it and when it dries it's right back the way it was.