A couple of points of clarification are needed here. Yes, many pieces of historic silver have literally been polished to death - that is because very harsh abrasive polishes and acidic dips have been used. The rule is this : If something works extremely quickly, almost instantaneously, that should raise the red-flag in your brain! Conservation scientists have conducted several studies of both commercial silver polishes & dips, as well as using selected pure materials for making their own polishes. Since commercial products are proprietary formulations (they won't tell you everything that is in them) and because they are made to act rapidly (to give the modern consumer instant gratification) they should only be used on silver which isn't considered heirloom or antique.
The polish that I recommend, over-and-over again, is to acquire some precipitated chalk (calcium carbonate) - otherwise known as whiting, which is easily acquired at your local Artist's supply store or from Fisher Scientific. Mix this with distilled water (not tap water) into a paste with the consistency of Dijon mustard (Pass the Poupon Please!). After polishing rinse thoroughly in distilled water with a very soft natural bristle brush - do not use a toothbrush or a metal wire brush!. Throughly remove all residues and rinse again in clean distilled water. Dry with soft, clean cloths, then use a blow-dryer to heat the surface to evaporate any remaining moisture which may be in the details of the chasing and engraving. At this point do nothing more than to store the silver in a friendly environment. I do not recommend that you get involved with any chemicals or lacquers and such - unless you know what you are doing and have all of the appropriate safety equipment. If an accident happens OSHA will not come by for a friendly visit!
Chemical dips have their place, but should be used selectively. I do not recommend that you get into the use of these chemicals. If you have a gilt layer which is very ephemeral, for instance, the use of a dip may be required. This is when you should call a conservator. Dips turn silver a matte white color and removes all tarnish, hence all signs of age and patina. The surface starts to re-tarnish immediately. The same is true for the electro-chemical cleaning method with baking-soda and aluminum.
To return to Mr. Millard's observations - yes, you should think hard before deciding to polish any object and you should be prepared to provide proper storage for that object following cleaning so that you slow down the necessity to re-polish the object continually.
That is all I have to say about this - I know that some folks might be tired of this topic. I will be happy to continue a dialogue off of the list for those who have more questions.
Cheers!
Dave
David Harvey
Associate Conservator,
Metals & Arms
The Colonial Williamsburg Foundation
P.O. Box 1776
Williamsburg, Virginia 23187-1776 USA
Voice: 757-220-7039
E-Mail: [log in to unmask]
-----Original Message-----
From: Millward, Peter [SMTP:[log in to unmask]]
Sent: Thursday, May 07, 1998 5:34 PM
To: [log in to unmask]
Subject: Re: Silver artifacts
The point about Will's suggestion and others like it is that ultimately
there is no silver left. The "TARNISH" used to be metallic silver and is
now some compound of silver caused by a chemical reaction that converts
it from silver to for example silver sulphide [the black you get from
using silver spoons to eat eggs]. Removing the tarnish leaves a nice
clean new silver surface waiting for the next suitable occassion to
become the next layer of tarnish. You can work out the end result for
yourslef. In the nd a plated object will need replating because theirs
so little left to become tarnish any more.
Peter Millward
Manager, Education & Visitor Services
Melbourne Museum
PO Box 666E, Melbourne, VIC 3000
ph 61 3 9651 8162 fax 61 3 9651 6378
mobile 61 418 326 667
email [log in to unmask]
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