Stainless steel sculpture and salt water

Dennis A. Baltuskonis <dbaltusk [at] trinity__edu> writes

>Texas Gulf coast city is having a recurring problem with a large
>"stainless steel" sculpture installation and would like to hear of
>extended actions to take toward maintaining the pieces.  The artist
>allegedly used an "inferior" grade of stainless steel, which does
>exhibit signs of rust within a year of each "cleaning".  The
>sculpture piece is located directly across from the sea wall and is
>therefore exposed year round to the gulf coastal salt water
>environment.  The sculpture is presently being 'maintained' by city
>public works department and although there is no documentation, I
>believe their treatment amounts to little more than 'scrubbing' to
>remove surface rust followed by 'waxing' (with an unknown past wax
>compound).  I new treatment proposal has been submitted (by someone
>in the city) which wants to scrub the surface with OSPHO (not sure
>what that is) followed by surface treatment with "lanacote" ...

I haven't got any experience with those products or with that
particular problem. However you may want to try to contact Texas A&M
university. I believe that there has been some research carried into
metals and sea water. At the bottom of
<URL:http://nautarch.tamu.edu/class/anth605/File9.htm> there is a
contact email for someone from the Nautical Archaeology program.
Although it's not exactly what you may be after, they may be able to
direct you to someone with more information.

A quick google search brings up a number of web sites referring to
OSPHO including
<URL:http://www.jamestowndistributors.com/ospho.htm>. As far as I
can gather it is a rust inhibiting paint with a greenish appearance.
It seems to be normally used as an undercoat. Now I gather the point
of the sculpture was to have the look of stainless steel so I doubt
that this product will be suitable. As far as I know there are no
clear rust inhibiting paints on the market. So I think the only
options open are to replace the sculpture with marine grade
stainless steel or to continue cleaning it (avoiding the use of
chlorine based cleaning agents). In the long term I think replacing
would be a better option. Any inhibitor just slows the rate of
corrosion but it must be applied properly to be effective and you
have the chance of the coating being damaged if it's exposed to the
weather and needing reapplication.


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                  Conservation DistList Instance 18:9
                  Distributed: Thursday, July 22, 2004
                        Message Id: cdl-18-9-005
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