From:
John Twilley <jtwilley@zzzzzzzzzzz>
Date:
Wed, 19 Jan 2005 01:25:16 -0500
Subject:
fire damaged rock
It may be possible to remove the grime by low pressure grit blasting using
walnut shell or corn cob granules (no jokes allowed). These are biodegradable
agricultural byproducts that you should be able to find sources for on the
web. One source is a company called Agrashell. They are available in sizes
ranging from that of very coarse sand to 200 mesh or smaller. For this kind of
application you would not want a grade that was too dusty.
These materials are used in metal finishing where a burnishing action is
required rather than cutting. If it is possible to remove the grime without
removing the outer grains of stone, this should do it. It may not be effective
on tarry smoke condensates, however.
Use an non-pressurized hopper feeder and put a drier in the air line to keep
condensation from causing the material to cake up or clog the nozzel. Start
with minimal pressure and work up to something that works.
John Twilley
Conservation Scientist
Tomas Lipps wrote:
Quoted text begins.Do you have any advice about cleaning stone that is heavily fire damaged?
End of quote.
- References
- message 00134: Drilling alabaster - Don Dougan (17 Jan 2005)
- Previous by Thread: message 00164: fire damaged rock - Charles Kibby (19 Jan 2005)
- Next by Thread: message 00138: Drilling alabaster - Bernd Buerklin (18 Jan 2005)
- Previous by Date: message 00165: Drilling alabaster - Pwwhitley (19 Jan 2005)
- Next by Date: message 00167: What Can Be Art? - Simon Buchanan (19 Jan 2005)
