Topica Loopframe_Guzzi Archive


Subject: Re: chrome and steel wool

Author: Robert Hawkes

Date: Jan 1, 2002, 6:45 PM

Post ID: 1709273309


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Elizabeth,
Some nice remarks you've attached to your e-mail. I used to work on restoring art and these remarks are well thought out. The various was of cleaning and restoring old stuff is always controversial. The best method is to work slowly and on small patches at a time. Few of us work this way though.
Bob
----- Original Message -----
From: Alacritas
To: Loopfram-@topica.com
Sent: Tuesday, January 01, 2002 8:24 PM
Subject: Re: chrome and steel wool


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Mguzz-@aol.com a *crit :so what is the best?
Hi Everyone,

I wish you all a Very Happy New Year and a great riding season for 2002!

In answer to the question what is the best polishing product - many answers. The first is that manufacturers keep changing their formulas without notice and it is difficult to recommend a product for that reason. In museums, we recommend using the least abraisive and most inert product and working your way up. If you just want to clean an already shiny surface, a solution of precipitated chalk can be sufficient - that way you don't overpolish the surface. Do not use this on for a heavy duty polishing job - you will hate my guts. Some people use gentle polishers, but with a harsh cloth - which defeats the purpose.

You can test the abraisiveness of a polishing product by polishing a piece of plexiglass. The scratches on the plexi are a good indicator of what the polish will do to your metal surface.

Solvol Autosol seems to be a popular product for heavy duty polishing of chrome - but I will check on the conservation distlist if it is still recommended. The important thing is to remove the residues. It is still ranked as a very abraisive product, but the abraisive material is more uniform than in other products, so causes less scratching.

I found some emails on polishing - perhaps too much on that subject - so reader be warned and can delete this e-mail now. Below are e-mails on chrome, removing residues, on polishing plastics and some talk on polishing brass and copper for those hard core polishing enthousiastics out there.

Cheers,

Elisabeth
72 Eldo

N.B. Many conservators are afraid of being sued (at least in the states) so I have just left their initials on the e-mails as I have not asked for permission to reproduce them.

Subject: Chrome
Date: 01-23-1999

C Uasked "What composes the metal chrome? How can we
clean and preserve an artifact made of chrome?"

Chrome is a layer of Chromium metal that is usually plated onto
steel (and sometimes other metal) objects to provide corrosion
protection and/or an aesthetic appearance. On steel objects there is
usually a layer of copper plating, and sometimes nickel as well,
between the steel and the chrome. This helps to stop the chrome from
peeling off.

Chrome plating is usually fairly hard. To clean it I would first
recommend wiping it with a detergent solution. If it is badly
scratched or corroded then there are "Chrome Polishes" available.
Try your local car parts supplier. Bear in mind, though, that
polishing will remove metal, so there are ethical issues to
consider.

G B
Objects Conservator
__________________________________________
Subject: removing polish residue
Date: 04-01-1994


Je: an old dry toothbrush (you know, only slightly
post-archaeological...). It's fast. Try to mask
surrounding areas in case you get too enthusiastic. Cheers


Conservation DistList Instance

Subject: Removing old polish residue
Date: 04-06-1994


With regard to removing polishing residues for small objects by running
them through an ultrasonic cleaner, proceed with great caution if the
object is plated. If a plated metal surface does not have perfect
adhesion between the plated layer and the substrate, the energy dose
from the ultrasonic bath can cause the catastrophic delamination. In my
experience, this delamination starts at the point of delamination and
proceeds by lifting a sinuously winding lines from the beginning
point---a phenomenon called filiform delamination. As far as I have
been able to determine once this has happened, there is not much to do
about it. This type of delamination happens very fast in an ultrasonic
cleaning bath and it makes you feel rather helpless. Since, it is
usually not possible to spot areas of poor adhesion in a plated piece of
metal by simple visual examination, I would not risk putting a plated
object into an ultrasonic bath.

S B

----------------------------------------------------------------------------------------------------------------

Date: 04-12-1999


>Can anyone tell me the correct steps to take in cleaning our 1936
>fire engine? I've vacuumed it and plan to wash it with cotton cloths
>dampened with distilled water. Can I, or should I use some type of
>polish to remove old water marks, oxidation, etc.?

Cleaning the exterior of a vehicle without scratching the finish is
a real challenge. Vacuuming with a soft natural bristle brush is
normally the recommended first step in cleaning dirty artifacts but
in this case the brushing action could grind the dirt and grit
particles into the finish. Sometimes the worst of the dirt can be
blown off with compressed air. The best method is to flood the
surface with water and flow the dirt off, but this isn't normally
possible with indoor collections and there is always the danger of
water working its way into crevices that are no longer weatherproof.
The next best thing is to mist small areas (i.e, one square foot at
a time) with a plant atomizer filled with distilled water and a drop
of liquid detergent, followed by wiping with a damp cotton cloth or
chamois. Use as much water as you see fit; enough to soften and
dislodge the dirt while controlling the run-off. Repeat with a clear
water mist and dry with a clean chamois or cotton cloth. Make sure
they're perfectly clean, otherwise they'll act like sandpaper on the
finish.

You can try a number of products to remove water marks and other
stains. Start with a soft white vinyl eraser (e.g.,Staedtler Mars
Plastic 526 50, or Faber-Castell Magic Rub1954). If that doesn't
work, try a commercial polish designed for acrylic plastics like
Plexiglas. Plexi is probably the most vulnerable surface you'll find
in any industrial collection. As a rule, if a product won't damage
Plexi, it won't harm any finish. (We test the abrasiveness of metal
polishes here with squares of clear Plexiglas, by the way.) Try the
Novus cleaners and polishes (Nos.1 & 2) or Meguiar's Mirror Glaze 17
Professional Plastic Cleaner or No. 10 Polish. The latter are
apparently used on modern aircraft canopies and they're popular with
aviation museums.

As for overall oxidation, you may be better off leaving it alone.
Once you start polishing, you could find yourself doing the entire
vehicle in order to get a uniform appearance. It's your call.

G P
Subject: Polishing fire engine
Date: 04-22-1999 >

A range of polishes and anti static cleaning products made
specifically for acrylics and recommended by ICI is manufactured here
in the United Kingdom.

P315 is a silicone free cleaning paste with a pH of 7.2 and is
ideally suited to the cleaning and removal of minor
blemishes,finer flatting marks and scratches. This product can
be used by hand or by a machine polisher.

L105 is a finishing solution which can be used to remove very
fine surface blemishes and minor imperfections, it too can be
applied by hand or a machine polishers.

P615 is a silicone free, pH 7.2 coarser grade paste designed to
be applied in conjunction with water and a machine polisher to
remove deeper abrasive marks.

These products were developed for the acrylics industry and outside
of conservation are primarily used by the aircraft industry and
builders of luxury yachts.

Full technical details are available from our offices here in
England and at Springfield Virginia.

M V
-----------------------------------------------------------------------------------------------

Subject: Brass polishes
Date: 01-13-1998


I would like to add a few thoughts to the thread on the use of brass
polishes and how this information could be conveyed to the general
public. I know C F, and I'm sure that he is well
acquainted (along with every furniture conservator) with the damages
caused by the use of commercial polishes on furniture brasses.

Ct F's and G B's observations on avoiding brass
polishes which contain ammonia are well taken. Ammonia is
incorporated into many commercial cleaning products (including glass
cleaners) because it is a powerful degreaser. However, ammonia has
a deleterious effect on copper-alloys, particularly brasses which
contain more than 15% zinc and other minor alloying elements (such
as lead, tin,and aluminum).

Very small percentages (ppm) of moist ammonia in the presence of air
forms soluble copper complexes and attacks the residual stresses
left in the microstructure from cold-working - hence it's name:
stress corrosion cracking. This form of corrosion is essentially a
form of dealloying. When this process is carried to it's extreme the
copper is redeposited onto the surface of the metal in a porous form
and the zinc may either be left in place as an insoluble compound
or effloresced as as soluble salt. A series of cracks radiate out
from the locus of the corrosion leaving the metal in brittle
condition. J M's poster with SEM photomicrographs at the last
AIC meeting in San Diego demonstrated the phenomenon perfectly.

The trouble with using such ammoniated polishes is that the residues
are almost never completely removed (unless ultrasonic cleaning is
employed), and crevice areas and pits become microscopic collection
areas and the locii for corrosion cells to form. Swab cleaning just
will not do it, if you don't believe me then examine what you think
is clean under the microscope.

Whenever I discuss cleaning options with the general public I always
make my first point a discussion on whether one should polish or
not--in many ways an aesthetic question, but becoming increasingly
important in terms of the issues of patina, attribution, and object
value (something the general public can always relate to!).
Polishing is essentially the refinishing of an object's surface and
should never be pursued without careful thought. If polishing will
be done, then I would only recommend the use of precipitated chalk
as a first step, and perhaps either a gamma or alpha alumina (mixed
with distilled water) as an alternative. I always warn the public
about the fact that such "safe" polishes will take more time and
elbow grease in use when compared to those polishes and dips which
harbor late-night television and seem to work instantaneously.
Still, all polish residues and all of the water must be removed too
(even inert particles can initiate microscopic corrosion cells). For
this I recommend a soft natural bristle brush used in hot distilled
water with a mild detergent and the use of a blow-dryer to evaporate
off the remaining moisture.


D H
Associate Conservator,
Metals & Arms


C F inquired about which proprietary brass/metal polishes
to recommend to the general public. This requires a long answer and
may spark some controversy, since we have to give the public some
straight answers or else we lose credibility. On the other hand, we
should also encourage people to know when they have a historically
valuable object and it is in poor condition that they should find a
professional conservator who is available to assess and treat the
objects. I would be willing to discuss this off list.

My short answer is that I use Simichrome polish as a final polish on
polished metals, after initial cleaning with other tarnish/corrosion
removal chemicals. I remove the Simichrome residue with acetone
and/or mineral spirits. It does contain approximately 13% ammonium
oleate, which is responsible for the ammonia odor. Two other
paste-type metal polishes, Peek and Solvol Autosol, essentially
contain the same ingredients; only the colorants used differ. My
decision to use this product was based on published silver polishing
research, evaluation of the MSDS and product literature, and
empirical experience. I most damage done to metals by ammonia-based
polishes is due to the fact that people do not rinse them off and
completely remove the residues. Perhaps a conservation
scientist/metallurgist has research data that elucidates how and
when the damage occurs: immediately upon application of the ammonia,
or over a period of time if allowed to seep into the porosities of
the alloy. I suppose the effect would depend upon the alloy
composition, degree of surface damage, etc..

P S
Objects Conservator

C F asked for a recommendation for ammonia free brass
polishes.

Perhaps you should avoid brass polishes altogether, and recommend
silver polishes instead. These tend to be less abrasive than brass
polishes. There are several available that are water or IMS based,
which are less hazardous to the user than Brasso that contains white
spirits, which now has a fairly low TLV. You could include in your
talk microphotographs of samples of brass that have been polished
with brass polish and silver polish to demonstrate how much harsher
the brass polishes are.

G B
Objects Conservator




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<DIV><STRONG><FONT color=#000080 size=4>Elizabeth,</FONT></STRONG></DIV>
<DIV><STRONG><FONT color=#000080 size=4>Some nice remarks you've attached to
your e-mail. I used to work on restoring art and these remarks are well
thought out. The various was of cleaning and restoring old stuff
is always controversial. The best method is to work slowly and on
small patches at a time. Few of us work this way
though.</FONT></STRONG></DIV>
<DIV><STRONG><FONT color=#000080 size=4>Bob</FONT></STRONG></DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title-@sympatico.ca href="mailto:ej-@sympatico.ca">Alacritas</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=Loopf-@topica.com
href="mailto:Loopfram-@topica.com">Loopfram-@topica.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, January 01, 2002 8:24
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: chrome and steel wool</DIV>
<DIV><BR></DIV><PRE>============================================================
PROSAVVY: GUARANTEED SATISFACTION WITH YOUR CONSULTANT!
With more than 1,800 pre-qualified consulting firms from
every major practice area, ProSavvy reduces the time/risks
with obtaining consulting services. GUARANTEED!
<A href="http://click.topica.com/caaae2vb1dfltb1FlG8b/ProSavvy">http://click.topica.com/caaae2vb1dfltb1FlG8b/ProSavvy</A>
============================================================</PRE>
<BR><B>Mguzz-@aol.com </B>a *crit :s<B>o what is the best?</B>
<P>Hi Everyone,
<P>I wish you all a <B>Very Happy New Year</B> and a great riding season for
2002!
<P>In answer to the question what is the best polishing product - many
answers. The first is that manufacturers keep changing their formulas
without notice and it is difficult to recommend a product for that
reason. In museums, we recommend using the least abraisive and most
inert product and working your way up. If you just want to
clean an already shiny surface, a solution of precipitated chalk can be
sufficient - that way you don't overpolish the surface. Do not use this on for
a heavy duty polishing job - you will hate my guts. Some people use gentle
polishers, but with a harsh cloth - which defeats the purpose.
<P>You can test the abraisiveness of a polishing product by
polishing a piece of plexiglass. The scratches on the plexi are a good
indicator of what the polish will do to your metal surface.
<P>Solvol Autosol seems to be a popular product for heavy duty polishing of
chrome - but I will check on the conservation distlist if it is <B>still</B>
recommended. The important thing is to remove the residues. It is still
ranked as a very abraisive product, but the abraisive material is more uniform
than in other products, so causes less scratching.
<P>I found some emails on polishing - perhaps too much on that subject -
so reader be warned and can delete this e-mail now. Below are e-mails on
chrome, removing residues, on polishing plastics and some talk on
polishing brass and copper for those hard core polishing enthousiastics out
there.
<P>Cheers,
<P>Elisabeth <BR>72 Eldo
<P>N.B. Many conservators are afraid of being sued (at least in the states) so
I have just left their initials on the e-mails as I have not asked for
permission to reproduce them.
<P><B>Subject: Chrome</B> <BR>Date: 01-23-1999
<P> C Uasked "What composes the metal chrome? How can we
<BR> clean and preserve an artifact made of chrome?"
<P> Chrome is a layer of Chromium metal that is usually
plated onto <BR> steel (and sometimes other metal) objects to
provide corrosion <BR> protection and/or an aesthetic appearance.
On steel objects there is <BR> usually a layer of copper plating,
and sometimes nickel as well, <BR> between the steel and the
chrome. This helps to stop the chrome from <BR> peeling off.
<P> Chrome plating is usually fairly hard. To clean it I would
first <BR> recommend wiping it with a detergent solution. If it is
badly <BR> scratched or corroded then there are "Chrome Polishes"
available. <BR> Try your local car parts supplier. Bear in mind,
though, that <BR> polishing will remove metal, so there are
ethical issues to <BR> consider.
<P> G B <BR> Objects Conservator
<BR>__________________________________________ <BR><B>Subject: removing polish
residue</B> <BR>Date: 04-01-1994 <BR>
<P> Je: an old dry toothbrush (you know, only slightly
<BR> post-archaeological...). It's fast. Try to mask
<BR> surrounding areas in case you get too enthusiastic. Cheers
<BR>
<P>
Conservation DistList Instance
<P>Subject: Removing old polish residue <BR>Date: 04-06-1994 <BR>
<P> With regard to removing polishing residues for small objects
by running <BR> them through an ultrasonic cleaner, proceed with
great caution if the <BR> object is plated. <B>If a plated
metal surface does not have perfect</B> <BR><B> adhesion between
the plated layer and the substrate, the energy dose</B> <BR><B>
from the ultrasonic bath can cause the catastrophic delamination. </B> In
my <BR> experience, this delamination starts at the point of
delamination and <BR> proceeds by lifting a sinuously winding
lines from the beginning <BR> point---a phenomenon called filiform
delamination. As far as I have <BR> been able to determine
once this has happened, there is not much to do <BR> about
it. This type of delamination happens very fast in an ultrasonic
<BR> cleaning bath and it makes you feel rather helpless.
Since, it is <BR> usually not possible to spot areas of poor
adhesion in a plated piece of <BR> metal by simple visual
examination, I would not risk putting a plated <BR> object into an
ultrasonic bath.
<P> S B
<P>----------------------------------------------------------------------------------------------------------------

<P>Date: 04-12-1999 <BR>
<P> ><B>Can anyone tell me the correct steps to take in
cleaning our 1936</B> <BR><B> >fire engine? </B>I've vacuumed
it and plan to wash it with cotton cloths <BR> >dampened with
distilled water. Can I, or should I use some type of <BR>
>polish to remove old water marks, oxidation, etc.?
<P> Cleaning the exterior of a vehicle without scratching the
finish is <BR> a real challenge. Vacuuming with a soft natural
bristle brush is <BR> normally the recommended first step in
cleaning dirty artifacts but <BR> in this case the brushing action
could grind the dirt and grit <BR> particles into the finish.
Sometimes the worst of the dirt can be <BR> blown off with
compressed air. The best method is to flood the <BR> surface with
water and flow the dirt off, but this isn't normally <BR> possible
with indoor collections and there is always the danger of <BR>
water working its way into crevices that are no longer weatherproof.
<BR> The next best thing is to mist small areas (i.e, one square
foot at <BR> a time) with a plant atomizer filled with distilled
water and a drop <BR> of liquid detergent, followed by wiping with
a damp cotton cloth or <BR> chamois. Use as much water as you see
fit; enough to soften and <BR> dislodge the dirt while controlling
the run-off. Repeat with a clear <BR> water mist and dry with a
clean chamois or cotton cloth. Make sure <BR> they're perfectly
clean, otherwise they'll act like sandpaper on the <BR> finish.
<P> You can try a number of products to remove water marks and
other <BR> stains. Start with a soft white vinyl eraser
(e.g.,Staedtler Mars <BR> Plastic 526 50, or Faber-Castell
Magic Rub1954). If that doesn't <BR> work, try a commercial polish
designed for acrylic plastics like <BR> Plexiglas. Plexi is
probably the most vulnerable surface you'll find <BR> in any
industrial collection. As a rule, if a product won't damage <BR>
Plexi, it won't harm any finish. (We test the abrasiveness of metal
<BR> polishes here with squares of clear Plexiglas, by the way.)
Try the <BR> Novus cleaners and polishes (Nos.1 & 2) or
Meguiar's Mirror Glaze 17 <BR> Professional Plastic Cleaner or No.
10 Polish. The latter are <BR> apparently used on modern aircraft
canopies and they're popular with <BR> aviation museums.
<P> As for overall oxidation, you may be better off leaving it
alone. <BR> Once you start polishing, you could find yourself
doing the entire <BR> vehicle in order to get a uniform
appearance. It's your call.
<P> G P <BR><B>Subject: Polishing fire engine</B> <BR>Date:
04-22-1999 >
<P> A range of polishes and anti static cleaning products made
<BR> specifically for acrylics and recommended by ICI is
manufactured here <BR> in the United Kingdom.
<P> P315 is a silicone free cleaning paste
with a pH of 7.2 and is <BR> ideally
suited to the cleaning and removal of minor
<BR> blemishes,finer flatting marks and
scratches. This product can <BR> be used
by hand or by a machine polisher.
<P> L105 is a finishing solution which can
be used to remove very <BR> fine surface
blemishes and minor imperfections, it too can be
<BR> applied by hand or a machine
polishers.
<P> P615 is a silicone free, pH 7.2
coarser grade paste designed to <BR> be
applied in conjunction with water and a machine polisher to
<BR> remove deeper abrasive marks.
<P> These products were developed for the acrylics industry and
outside <BR> of conservation are primarily used by the aircraft
industry and <BR> builders of luxury yachts.
<P> Full technical details are available from our offices here in
<BR> England and at Springfield Virginia.
<P> M V
<BR> -----------------------------------------------------------------------------------------------

<P>Subject: Brass polishes <BR>Date: 01-13-1998 <BR>
<P> I would like to add a few thoughts to the thread on the use of
brass <BR> polishes and how this information could be conveyed to
the general <BR> public. I know C F, and I'm sure that he is well
<BR> acquainted (along with every furniture conservator) with the
damages <BR> caused by the use of commercial polishes on furniture
brasses.
<P> Ct F's and G B's observations on avoiding brass
<BR> polishes which contain ammonia are well taken. Ammonia is
<BR> incorporated into many commercial cleaning products
(including glass <BR> cleaners) because it is a powerful
degreaser. However, ammonia has <BR> a deleterious effect on
copper-alloys, particularly brasses which <BR> contain more than
15% zinc and other minor alloying elements (such <BR> as lead,
tin,and aluminum).
<P> Very small percentages (ppm) of moist ammonia in the presence
of air <BR> forms soluble copper complexes and attacks the
residual stresses <BR> left in the microstructure from
cold-working - hence it's name: <BR> stress corrosion cracking.
This form of corrosion is essentially a <BR> form of dealloying.
When this process is carried to it's extreme the <BR> copper is
redeposited onto the surface of the metal in a porous form <BR>
and the zinc may either be left in place as an insoluble compound
<BR> or effloresced as as soluble salt. A series of cracks radiate
out <BR> from the locus of the corrosion leaving the metal in
brittle <BR> condition. J M's poster with SEM photomicrographs at
the last <BR> AIC meeting in San Diego demonstrated the phenomenon
perfectly.
<P> The trouble with using such ammoniated polishes is that the
residues <BR> are almost never completely removed (unless
ultrasonic cleaning is <BR> employed), and crevice areas and pits
become microscopic collection <BR> areas and the locii for
corrosion cells to form. Swab cleaning just <BR> will not do
it, if you don't believe me then examine what you think <BR> is
clean under the microscope.
<P> Whenever I discuss cleaning options with the general public I
always <BR> make my first point a discussion on whether one should
polish or <BR> not--in many ways an aesthetic question, but
becoming increasingly <BR> important in terms of the issues of
patina, attribution, and object <BR> value (something the general
public can always relate to!). <BR> Polishing is essentially the
refinishing of an object's surface and <BR> should never be
pursued without careful thought. If polishing will <BR> be
done, then I would only recommend the use of precipitated chalk
<BR> as a first step, and perhaps either a gamma or alpha alumina
(mixed <BR> with distilled water) as an alternative. I
always warn the public <BR> about the fact that such "safe"
polishes will take more time and <BR> elbow grease in use when
compared to those polishes and dips which <BR> harbor late-night
television and seem to work instantaneously. <BR> Still, all
polish residues and all of the water must be removed too <BR>
(even inert particles can initiate microscopic corrosion cells). For
<BR> this I recommend a soft natural bristle brush used in hot
distilled <BR> water with a mild detergent and the use of a
blow-dryer to evaporate <BR> off the remaining moisture.
<BR>
<P> D H <BR> Associate Conservator, <BR>
Metals & Arms <BR>
<P>C F inquired about which proprietary brass/metal polishes <BR>
to recommend to the general public. This requires a long answer and
<BR> may spark some controversy, since we have to give the public
some <BR> straight answers or else we lose credibility. On
the other hand, we <BR> should also encourage people to know when
they have a historically <BR> valuable object and it is in poor
condition that they should find a <BR> professional conservator
who is available to assess and treat the <BR> objects. I
would be willing to discuss this off list.
<P> My short answer is that I use <B>Simichrome</B> polish as a
final polish on <BR> polished metals, after initial cleaning with
other tarnish/corrosion <BR> removal chemicals. I remove the
Simichrome residue with acetone <BR> and/or mineral spirits.
It does contain approximately 13% ammonium <BR> oleate, which is
responsible for the ammonia odor. Two other <BR> paste-type
metal polishes, Peek and Solvol Autosol, essentially <BR> contain
the same ingredients; only the colorants used differ. My
<BR> decision to use this product was based on published silver
polishing <BR> research, evaluation of the MSDS and product
literature, and <BR> empirical experience. I most damage
done to metals by ammonia-based <BR> polishes is due to the fact
that people do not rinse them off and <BR> completely remove the
residues. Perhaps a conservation <BR> scientist/metallurgist
has research data that elucidates how and <BR> when the damage
occurs: immediately upon application of the ammonia, <BR> or over
a period of time if allowed to seep into the porosities of <BR>
the alloy. I suppose the effect would depend upon the alloy
<BR> composition, degree of surface damage, etc..
<P> P S <BR> Objects Conservator
<P> C F asked for a recommendation for ammonia free brass
<BR> polishes.
<P> Perhaps you should avoid brass polishes altogether, and
recommend <BR> silver polishes instead. These tend to be less
abrasive than brass <BR> polishes. There are several available
that are water or IMS based, <BR> which are less hazardous to the
user than Brasso that contains white <BR> spirits, which now has a
fairly low TLV. You could include in your <BR> talk
microphotographs of samples of brass that have been polished <BR>
with brass polish and silver polish to demonstrate how much harsher
<BR> the brass polishes are.
<P> G B <BR> Objects Conservator <BR> <BR>
<BR> <PRE>============================================================
Enter to Win Free Maid Service and More from Pfizer!
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