fire damaged rock

Quoted text begins."traditional stonecleaning acid. . . in crystals?" is that something
other than muriatic acid, George?
End of quote.

Thomas,
My thought definitely needs more thought.
The stuff I spoke of is not muriatic acid, but some witch's brew that has
been used to clean granite monuments for years. It comes in a crystalline
form and is added to water , dissolved and brushed on and then rinsed off to
remove stains. Usually a cup to a gallon of warm water gives you the
standard solution. It works best on granite and other hard stones. Its not
for use on marble, as it will etch the surface. Changing the ratio of
crystals to water will change the strength. Its definitely a strong acid and
safety is a must. It works best on unpolished , and rock faced monuments.
As I learn more about the walls, I suspect that this stuff is not right for
your job.
If you want to follow up on this , I'll gladly pass on the necessary
information for you to get some.
I'm glad to hear that none of your family was in a fire!

George Graham