In a message dated 12/20/99 11:05:54 AM Eastern Standard Time,
[log in to unmask] writes:

> Ken or others, in the typical watersoak masonry cleaning (for, e.g.,
>  limestone) what role (if any) do the widely varying amounts of impurities
in
>  local water supplies play in the process?

Sharpshooter,

Usually, in my opinion, not a whole hell of a lot, at least for NYC water,
though it is prudent to consider filtering when looking at a new project and
doing on-site tests. You would not want to use water that is higher in
acidity than the local rainfall, for some unfathomed reason of logic. Water
with a lot of iron in it or other unusual metals can discolor the stone,
which has been rumored to happen in NYC. Using water with high concentrations
of mud or frog spawn in it may defeat the intended effect. Also, keep in mind
that watersoak cleaning is not PC during droughts.

][<en