Coatings for outdoor sculpture

Isabel M. Coryat <impa [at] valstar__net> writes

>George Hagerty <ghagerty [at] mfa__org> writes
>
>>I'm in the process of researching any new coatings that people may
>>know of, have tried, or can direct me to publications about for the
>>protection of outdoor sculpture composed of cast iron.
>
>...  Last but not least, I found a very
>intriguing note on Paul W. Bartlett hand written notes (copies of
>which I have on my files) referring to iron, and I quote "the Bower
>Borff process is a method of turning iron permanently black and
>rendering it rustless".

Martha Goodway presents an overview of bower-barffing in

    The patination of iron by bower-barffing.
    In Metal Plating and Patination
    (ed. Susan La Niece and Paul T. Craddock),
    Butterworth-Heinemann Pub., 1993., pp. 155-160.

The following abstract was imported from CHIN:

    Abstract: The bower-barff process was a patented method of
    developing a protective, aesthetically pleasing, velvety black
    surface on iron. The process had two essential steps: the first
    was the intentional production of a light layer of flash rust by
    exposing the iron to steam; this was followed by conversion of
    the rust to magnetite, which is black, by hydrogen reduction
    using ordinary producer gas. The method had many different
    applications, from utilitarian water pipes to highly decorated
    "fire proof" cast iron libraries. Hydrogen reduction as a
    conservation treatment was also a 19th-century development that
    had similar features but made no reference to bower-barffing.


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                  Conservation DistList Instance 13:42
                Distributed: Wednesday, February 2, 2000
                       Message Id: cdl-13-42-007
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