The following from Robert Waterhouse <[log in to unmask]>
Dear list,
I'm currently trying to decontaminate, clean and hopefully conserve an
object found on a mine dig I am involved with. It is a leather flap valve,
possibly from a water pump or a ventilating machine, but is reinforced and
weighted with riveted wrought iron plates. The mine is a sulphide one
(copper and arsenopyrite), meaning that it has been impregnated with mine
water which from a chemical point of view is dilute sulphuric acid.
I have been soaking it in tapwater, in a plastic bowl, in the hope that the
acid will be drawn out, and this seems to be working. However, the red
corrosion product on the surface of the iron is dissolving away, leaving a
black surface to the metal. I am concerned that the acid may be acting on
the metal still.
Am I doing the right thing? If not, what should I be doing, and how can I
stabilise both the iron and the leather, especially when it is removed from
the water permanently?
Although I have the CBA First Aid For Finds manual, it does not mention
such situations.
Help!
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Dr Peter Claughton,
Blaenpant Morfil, nr. Rosebush, Clynderwen, Pembrokeshire, Wales SA66 7RE.
Tel. +44 (0)1437 532578; Fax. +44 (0)1437 532921; Mobile +44 (0)7831 427599
Hon. University Fellow
School of Historical, Political and Sociological Studies (Centre for South
Western Historical Studies)
University of Exeter
E-mail: [log in to unmask]
Co-owner - mining-history e-mail discussion list.
See http://www.jiscmail.ac.uk/files/mining-history/ for details.
Mining History Pages - http://www.exeter.ac.uk/~pfclaugh/mhinf/
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