Corrosion

Lisa Young <conserveit [at] earthlink__net> writes

>I am currently working on space related aluminum alloys (30+ years
>of age) which are combined with copper, magnesium, zinc and other
>white metals in trace amounts. Recent analysis of the corrosion
>forming on the aluminum was identified by SCMRE as cuprous chloride
>with some amounts of aluminum oxide in the mix, but primarily it was
>copper chloride.  In regards to treatment, I was looking for advice
>or experience with adding corrosion inhibitors to either the metal
>(after it is cleaned) or the coating.  I was hoping to use
>benzotriazole to inhibit the copper from corroding further, but was
>not sure if anyone has found this to be harmful to aluminum or other
>white metals.

David Hallam (National Museum of Australia) and I did some simple
tests on the use of BTA on 2000 series (Al/Cu) Aluminium alloys in
the late 1980's. As far as I can recall, there were no adverse
reactions between the aluminium and BTA, and it did inhibit
corrosion. I would not expect there to be any problems with zinc,
magnesium or other  metals.

George Bailey
Objects Conservator
Australian War Memorial


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                  Conservation DistList Instance 15:30
                 Distributed: Tuesday, October 9, 2001
                       Message Id: cdl-15-30-001
                                  ***