Coatings for storage cases

On 28 July Mark Vine asked about the possibility of a zinc
metallised steel storage container off-gassing & damaging paper
artifacts within.

The zinc coating should not cause any problems to paper. Zinc is
either electroplated or melted onto steel to provide corrosion
protection, ie to stop the steel rusting, and there should be no
off-gassing at all. This is called galvanizing. There are some paint
systems that are zinc rich to provide corrosion protection. They
tend to have a grey, non-metallic matte appearance & may off-gas for
a while, as any paint system will.

If anything, the paper may be harmful to the zinc metal. Zinc can be
corroded by some organic vapours. The most common zinc corrosion
products are zinc oxides and carbonates. They are usually white with pH
around neutral, so they shouldn't pose a problem to paper.

George Bailey
Objects Conservator
Australian War Memorial
Treloar Centre for Conservation
4 Callan St, Mitchell, A.C.T. 2911
Australia
+61 6 241 6122
Fax: +61 6 241 7998

                                  ***
                  Conservation DistList Instance 10:15
                  Distributed: Friday, August 2, 1996
                       Message Id: cdl-10-15-006
                                  ***