Marble

A stately home custodian without access to the list has asked for
advice concerning an old marble fireplace with decorative relief.
The fireplace has considerable soot damage and requires cleansing
but the custodian is worried by what appears to be a salt like
precipitate on the surface of the relief, to the touch it apparently
appears as though the surface is crumbling away. Has anyone
suggestions as to what might be the cause of this precipitate and
might it be harmful?

In the past the custodian has used an alcohol ethoxylate cleansing
agent, Synperonic A7, and a potassium methyl cyclohexyl oleate
cleansing agent, Vulpex, to cleanse heavy deposits from marble and
tile surfaces in the collection.

In this instance there is a worry however arising from the unknown
precipitate and what effect solutions might have on it.

Mark Vine
Conservation Resources
Cowley, England


                                  ***
                  Conservation DistList Instance 16:46
                 Distributed: Friday, January 31, 2003
                       Message Id: cdl-16-46-025
                                  ***