Brass

Michiel Langeveld <info [at] metaalrestaurator__nl> writes

>During washing of brass objects in water, the brass stains from gold
>to brown. Can anyone advise me on the use of inhibitors or other
>methods to avoid this staining?

I'm not familiar enough with the chemistry of brass to tell you what
is going on but I can share a method used in our lab for cleaning
metal. We often clean stainless steal parts of instruments with
Wenol paste (rubbed on and off with cotton wool to remove staining).
To remove the paste residue the parts are then placed in a beaker of
petroleum spirit and placed in an ultrasonic bath for 10 minutes.
This step is repeated with ethanol. I do not know if this will work
with brass and it would be good to test this residue removal method
on a scrap piece of brass.

Rachel White
PhD student (Science)
University of Technology, Sydney
Australia


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                  Conservation DistList Instance 18:9
                  Distributed: Thursday, July 22, 2004
                        Message Id: cdl-18-9-007
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