Bloom on lead

Maria Saffiotti Dale <msaffiottidale [at] lvm__wisc__edu> writes

>I am seeking information on the recommended treatment, routine
>maintenance, and optimal display of a lead sculpture (Raymond
>Duchamp-Villon, "Le Cheval", 1914, cast 1950s; ex-Morton Neumann
>Family collection) which regularly "blooms." We have been
>maintaining it in-house by gently reducing the white oxide layer
>with very fine #0000 synthetic pads followed by the application of a
>coat of Renaissance wax.

Until you remove the wood from the lead you won't solve the problem
(unless you significantly reduce the humidity). The lead is oxidised
then carbonated by the joint affect of acetic acid from the wood and
moisture and carbon dioxide from the air to produce basic lead
carbonate, a white powder, very toxic.

No treatments nor coatings will significantly solve your problem, as
the aggressors are moisture and acetic acid and carbon dioxide which
can permeate the coatings. Different woods exude acid at a different
rate - check and see how aggressive your wood is - as a rule of
thumb, old hard wood is safer than new soft wood or laminates, but
this rule has its exceptions.

Linda Cannon


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                  Conservation DistList Instance 18:40
                 Distributed: Monday, February 28, 2005
                       Message Id: cdl-18-40-007
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