Tenax wax

Vanessa Roth <vanessaroth [at] hotmail__com> writes

>I have been asked to provide recommendations on an outdoor marble
>sculpture. The sculpture was originally highly polished black and
>white marble. It is now quite dull in appearance and the black areas
>have faded to grey.  The artist recommended applying Tenax paste wax
>every six months to maintain the polished appearance, but this has
>not been carried out.  Does anyone know what this wax is made from
>and whether it can be recommended as a maintenance treatment for
>marble?

I have never seen or heard of Tenax wax.  I found an MSDS on it that
was quite cryptic:  manufactured in Italy, has a straw/opalescent
color, contains acetone as the only hazardous ingredient
(supposedly!) and is partially miscible with water.  This sounds
like a sort of emulsion in acetone. The straw color may suggest a
carnauba wax mixture which is sometimes used on outdoor metal
sculpture.  Using wax on outdoor marble can be problematical, but
since the artist requested it and was probably applied as part of
the manufacture, perhaps it should be done.  I don't see why another
wax formulation could not be substituted, thereby avoiding the use
of the unknown products in Tenax, but purists may disagree.  The
cloudy surface you observe, however, may be due to remnants of the
old, degraded wax, or perhaps the effects of moisture trapped under
the old coating. Cleaning off the aged residues and re-waxing may
restore the appearance, but the stone may also be weathered badly
and lost the original polish.  More research and testing would seem
to be in order.  Other than that I cannot be very helpful, alas.

Linda S. Roundhill
Art and Antiquities Conservation
18121 157th Ave NE
Woodinville, WA 98072
425-481-0720


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                  Conservation DistList Instance 18:12
                  Distributed: Friday, August 13, 2004
                       Message Id: cdl-18-12-003
                                  ***