Corrosion layers on brass sundial

I have been asked for advice on removing a thick greenish patina
from a brass sundial.  I have been told it is thick (and adherent)
because the sundial was sprayed (accidentally) with fertilizer. My
background in corrosion control suggests methods for corrosion
product removal but they are fairly vigorous. Could anyone direct me
to specific removal procedures which are less harsh?

Graham Sussex
Institute of Metals and Materials
Melbourne

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                  Conservation DistList Instance 10:1
                 Distributed: Wednesday, June 19, 1996
                        Message Id: cdl-10-1-005
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