Consolidant for sandstone

Dara Zitzmann <d_zitzmann [at] yahoo__com> writes

>We will be working on a sandstone monument that has severely
>deteriorated.  We need to consolidate the stone, however as it is
>located in Washington DC, we cannot use Prosoco's Conservare OH.
>Does anyone on the DistList have suggestions for an acceptable
>sandstone consolidant that can be used in the District?

ProSoCo has put on the market an alternative to the OH specifically
designed for use in the states affected by the OTC VOC regulations.
It does not have a track record yet. I would tend to avoid the
alkali silicates that are available (Conproco's Start comes to
mind), simply because they have an historically poor track record,
as they tend to be deposited at the surface, thereby creating a
crust. Some VOC compliant water repellents are siloxane-silane
blends that might tend to have some consolidating effect, but I
would certainly discuss this with a manufacturer.

Lorraine Schnabel
Architectural Conservator


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                  Conservation DistList Instance 20:16
               Distributed: Wednesday, September 27, 2006
                       Message Id: cdl-20-16-003
                                  ***