Smoke stain on marble

Eoin O Riabhaigh <sculpres [at] indigo__ie> writes

>Having restored a large 200 year old marble sculpture recently, some
>deep orange staining remains. Though the piece is now in a beautiful
>condition, and the gallery curator is very satisfied with the
>restoration, I would like to remove the remaining seemingly
>irremovable blemishes. Any advice out there?

I have had success with the removal of some staining in marble by
making a poultice of Laponite and 3% household hydrogen peroxide.
Once gelled and in place on the stain, I will drip a small amount of
30% hydrogen peroxide into the Laponite. Monitor closely and clear
completely with distilled water.

Craig Deller
The Deller Conservation Group, Ltd
Geneva, Illinois  USA
Conservation Services for Historic Furniture and Objects

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                  Conservation DistList Instance 12:74
                 Distributed: Thursday, March 18, 1999
                       Message Id: cdl-12-74-001
                                  ***