Metal polish

Tom Dixon <tom.dixon [at] ngv__vic__gov__au> writes

>I have used Nevr Dull <URL:http://www.eagleone.com/> occasionally
>over many years, but not often or regularly. ...
>
>Does anyone on the list know the composition?  Has anyone any
>comment on the safety and effectiveness of Nevr Dull they'd care to
>share?  What do we as conservators do when faced with a product like
>this that seems to work well but which we do not know the contents?

I wrote the The George Basch Co., Inc., that makes Nevr-Dull Magic
Wadding Polish in 1994, and received the same response: "We can not
give out any info other than it is a (sic) oil base product with
mild abrasive.  We sell to many museums and have no problem with
using NEVR-Dull on any metals!".

The good news is that way back in 1980, CCI analyzed the product and
published the results in their Analytical Research Services
(ARS)series (ARS Number 1729).  Infrared spectrophotometry and
scanning electron microscopy (SEM) with electron beam X-ray
microanalysis (EDXRA).  The analyses revealed the following
components:

   "The white powder which adheres to the fibres is principally
    china clay or kaolin and finely ground quartz (Al2O3.2SiO2.2H2O
    Plus SiO2).  A small amount of hematite (Fe2O3) was also
    present.  No Cl or S were detected in the SEM.  The lack of
    sulfur would rule out the presence of thiourea. The large dark
    inclusions, although resinous in appearance, are anisotropic.
    The IR spectrum did not show the presence of an organic, but
    rather indicated clay type compounds which could contain
    potassium, calcium, magnesium and sodium.  Small amounts of
    sulfur, chlorine, iron and titanium were also detected in the
    SEM."

Of course, proprietary products are subject to change in composition
without notice from the manufacturer, so the company may have
changed some components since this analysis was done 24 years ago.
My educated guess would be that it hasn't changed by much.  I've
used the product in firearms conservation treatments where I needed
a very mild abrasive/solvent "dry" method. I've found it more
effective, if not as convenient, to use an oil-based corrosion
solvent such as WD-40 and some mild abrasive.  I don't find
NEVR-Dull to be very effective on copper alloys, or heavily oxidized
iron-based alloys.  I certainly have not observed any deleterious
effect, and I always use straight solvent to remove traces of any
polishing compound after cleaning.  Unless they drastically changed
the formula, NEVR-Dull has the advantage over metal polishes such as
Simichrome, Solvol Autosol, and Peek, of not containing any
ammoniated compounds, that can cause stress corrosion cracking in
copper alloys.

You should be able to obtain the Materials Safety Data Sheet (MSDS)
which should list the solvent and any health concerns.  The
manufacturer is required by US law to list any toxic components and
health and safety/handling concerns.

My policy with unknown product components is to try to find out as
much as possible by various means.  There are basic conservation lab
tests, such as the modified Oddy test, and other empirical
real-world tests that one can devise and perform.  Occasionally,
I've sent materials samples out to an outside lab if I required an
identification of the components, but that usually runs
$200-$300/sample.  Ultimately, it boils down to not using a product
if the company cannot or will not provide clear information on the
components, and there are alternative products or formulae
available.

Paul S. Storch
Senior Objects Conservator
Daniels Objects Conservation Laboratory (DOCL)
B-109.1, Minnesota History Center
345 Kellogg Blvd. West
St. Paul, MN  55102-1906
651-297-5774
Fax: 651-297-2967


                                  ***
                  Conservation DistList Instance 17:54
               Distributed: Wednesday, February 18, 2004
                       Message Id: cdl-17-54-010
                                  ***