Stains on marble

Eric Miller <eric.g.miller [at] btinternet__com> writes

>We are currently cleaning a marble fireplace that has yellow/brown
>tar stains that do not respond to our attempts at removal. Laser
>cleaning works but it turns the marble yellow. (A 1999 DistList
>entry affirms Synperonic N, but this is no longer available.) Any
>suggestions?

We have found  that by using a poultice of whiting with hydrogen
peroxide, left over the area, it will gradually draw the stain out,
though constant checking needs to take place. Obviously this is for
white based marble

Ben Hodgetts
Conservator


                                  ***
                  Conservation DistList Instance 22:54
                 Distributed: Wednesday, March 25, 2009
                       Message Id: cdl-22-54-007
                                  ***