Wax paste composition for outdoor bronze

Zee-Young Chin <zychin14 [at] hotmail__com> writes

>I am a conservator at Samsung Museum of Art in Seoul. We have
>outdoor bronze sculptures that are cleaned and coated every two
>years or so. One of our contacts working in the US told us several
>years ago to make our own wax using a ball mill. The ingredients
>were: Carnauba, beeswax, dammar in turpentine and lavender oil.
>
>Can someone tell me what role does the lavender oil play in this
>mixture?

Lavender essential oil is a complex compound consisting of at least
150 chemical constituents. It is usually predominantly made up of an
alcohol, linalool (up to 40%) and an ester, linalyl acetate. linalyl
acetate has an antimicrobial and anti fungal action so this could be
a possible reason for including it in the wax mixture. However, the
active ingredients in lavender are pretty volatile so the effect
would not be long-lasting.In order to preserve the life of an
essential oil it needs to be stored in a coloured glass bottle in a
cool place--and even then an oil such as lavender will only have a
shelf life of about a year (ie it will no longer be effective
medicinally or chemically)  As a former aromatherapist and now a
conservator, I feel it is unwise to use essential oils in contact
with historic objects, or as a part of a treatment unless the
chemical changes that take place over time can be fully understood
(which they usually can't with essential oils, possibly due to the
mysterious and unsynthesizable synergy that plant compounds have).

I wonder if this recipe was formerly a domestic one and the lavender
was included for it's pleasant aroma more than anything else?

Mela Penrhys Jones
Textile Conservator
The Textile Conservation Centre
University of Southampton
Uk


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                  Conservation DistList Instance 22:60
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