Dewaxing large iron objects

At Colonial Williamsburg we have a large number of iron objects that
were treated back in the 1970s and given pigmented wax coatings. We
are currently retreating objects from some of these sites and have
had success removing the wax using solvent baths for the small
objects. However many of the objects are quite large and are not
suitable for dewaxing using the solvent method.

We have been experimenting with a technique used in the past by the
British Museum and published in Conservation News by Simon Dove. It
involves applying a poultice of diatomaceous earth and 5% polyvinyl
acetate solution and then baking the object at a temperature just
above the melting point for the wax for 24 hours. So far we have not
had particular success with this technique and are interested to
know if others have used it successfully and might give us pointers?
Alternatively has anyone investigated other techniques for removing
wax from archaeological iron? These objects are too large for the
solvent still technique pioneered by the Maryland Archaeological
Conservation lab and considering their size we would like to limit
the amount of solvents used.

Ellie Rowley-Conwy
Archaeological Conservation Intern
Colonial Williamsburg Foundation


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                  Conservation DistList Instance 26:5
                  Distributed: Saturday, June 23, 2012
                        Message Id: cdl-26-5-015
                                  ***