Cor-ten steel sculpture

We have an unpainted Cor-ten steel sculpture in our collection,
about 20 years old, that has been hit often by graffiti vandals and
subsequently by harsh graffiti-removal chemicals.  The resulting
discoloration could also be due to the trees above the sculpture or
our generally wet weather.

So, I am interested to hear about various experiences anybody may
have had with Cor-ten:  is it better to use an anti-graffiti
coating/sealer or leave the metal bare.  Are there any obvious
weathering patterns of Cor-ten; is the material affected differently
by different climates?

Would it be a possibility to totally clean off the present
discoloration (i.e. remove the oxidized layer) and let it weather
again without weakening the structure too much?  And this could only
be considered if there were some guarantee that we could avoid the
same discoloration in the future.

I'm also interested in finding out about any other sources of
information--research or other published material about Corten in
general and artwork made of Corten.

If anybody has any advice or good stories, they would be greatly
appreciated. Thanks.

Patricia Favero
Public Art Registrar,
Seattle Arts Commission

                                  ***
                  Conservation DistList Instance 12:6
                 Distributed: Wednesday, June 24, 1998
                        Message Id: cdl-12-6-012
                                  ***