Brass

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?

The brass is washed by putting it under a running tap for
approsimately 10 minutes, after that it should be washed 3 times in
successive baths of demineralised water to remove as much chemical
residues from cleaning procedures as possible, but staining occurs
before all washing is finished (sometimes already under the running
tap, but not always). I`d like to rinse/wash the brass this long to
remove as much chemicals as possible that are left by the cleaning
method I use (typical: the brass is cleaned by dipping in a bath of
0.5M EDTA (ethylenediaminotetraacidicacid) at pH=10, it is shortly
rinsed with water, brushed off with non-ionic soap in water and then
put in an ultrasonic bath to remove loosened corrosion and dirt).

Michiel Langeveld
M. Langeveld Metaalrestauratie
Zamenhofstraat 150
Unit 236-238
1022 AG Amsterdam
+31 6 50218260
The Netherlands


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                  Conservation DistList Instance 18:8
                 Distributed: Wednesday, July 21, 2004
                        Message Id: cdl-18-8-038
                                  ***