[MassHistPres] Soda blasting interior brick walls?

[Ward Hamilton at Olde Mohawk Historic Preservation]

Interviewed a soda-blasting company owner and walked through the client's
house in Boston's South End today with him. He insisted that, in his
experience, thoroughly soda-blasting interior brick to clean and remove
any residual paint, plaster, or dirt might do more damage to the brick
than hitting it for a briefer period of time with what he described as a
lighter "sand-type" media (which he called "Green Lightning").

I gave him a couple of sample bricks with and without paint to test, but
it was his opinion that any media is going to eat into the brick surface
somewhat, and that as long as he used a lighter media (and not the heavy
"Black Beauty" sand used in industrial sandblasting) the brick should be
OK, especially as it is interior masonry not exposed to weathering and
moisture.

I have a real aversion to the idea of using sand-type blasting or
abrasives on bricks, so I am not sure what to make of this fellow's
insistence on blasting something harder than soda against the walls. Do
you have any thoughts on this situation? We are still trying to find
another vendor to bid on soda-blasting (or whatever "blasting" is
appropriate), to compare against New England Soda Blasting.

If you have any recommended soda-blasting companies that you would be
willing to refer to us we'd appreciate it.  Thanks in advance for your
advice, thoughts and input re this and/or other techniques.


Ward Hamilton

OLDE MOHAWK HISTORIC PRESERVATION INC
877.622.8973 online at OldeMohawk.com
Slate Roofing | Masonry | Restoration