Caulking outdoor sculpture

Does anyone have experience or know of a suitable caulking for an
outdoor sculpture?  The surfaces to be caulked would be metal to
ceramic and metal to metal.  There is already a black flexible
caulking which appears to be silicone.  It is in good condition but
does not adhere well to the surfaces.

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                  Conservation DistList Instance 12:51
                Distributed: Tuesday, December 15, 1998
                       Message Id: cdl-12-51-029
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