14/08/2017 Chiswick Curates, Silver & Objects of Vertu
Ahead of the Silver & Objects of Vertu auction on 31 October, we asked Head of Department John Rogers to share his expertise on how to clean silver. He considers three different methods and weighs up the pros and cons of each.
'The cleaning and care of silver is so important for its preservation and to maximise its decorative appeal. It need not be the odious and laborious task it is often considered to be.' - John Rogers
Silver is combined with other metal to make it workable and not too soft, notably copper and antimony. These added metals contribute to the tarnishing that silver experiences.
‘The way in which silver is cleaned should help prevent tarnishing. However, if silver is kept in the open air (i.e not behind glass) it will naturally begin to tarnish lightly as it reacts to sulphur and other compounds in the air that will expedite tarnishing.’ – John Rogers
A fundamental element of cleaning silver, deemed an essential prerequisite by John to all practices, is the Goddards silver cloth. This silver cloth comes highly recommended as it can easily remove the light casual tarnish that builds up from day to day exposure. It leaves little mess and is gentle to the surface of the silver.
When silver items also have non-silver elements, for example wooden handles on teapots, this can be the only way to clean such an item as they cannot be submerged in boiling water.
This pink fabric-like material is especially good at removing stains from the surface of salvers and it is good for thicker tarnish that has built upon over many years, which a silver cloth cannot satisfactorily remove.
As a proprietary polish, this does abrase the surface of the silver and chemically remove a small amount of the silver. Overuse can lead to the wearing down of hallmarks, a lack of crispness in decoration and the thinning of edges and high points, which can lead to holes.
'For example, a typical George III teapot that has got smudged hallmarks and unclear bright-cut decoration due to being over polished will be worth less than a comparable example without this.' - John Rogers
If holes have formed from the edges being polished too much this will devalue the piece further even if it is restored.
'It is a somewhat messy procedure so I recommend wearing marigolds and using a cloth to polish the dark cleaning residue that the pink cloth leaves. Then once this is removed, use another cloth to buffer the surface and remove any last traces. Finally finish off with the Goddard’s silver cloth to give a shine.' - John Rogers
This method involves electrolysis whereby the bicarbonate acts as an oxidising agent and the tarnish is transferred to the aluminium. In order to do this, line a vessel with the shiny side of aluminium foil, add bicarbonate of soda (a level table spoon in a mixing bowl should do), add the item in and cover with boiling water. Remove the item after ten minutes or so, rinse and rub off the residual tarnish with a cloth, return to the solution if needs be and finish with a Goddards silver cloth to shine.
This method doesn’t remove any silver from the surface like a proprietary polish. It is useful for cleaning a batch of items, especially flatware and it is useful to remove tarnish that has built up in the hard to reach areas.
Some collector's have noted that this method can ‘bleach’ the appearance of silver and leave it overly white. However, it is definitely a useful method and one that works particularly well with items such as flatware, which have a considerable build-up of stubborn tarnish.
'A good option is to combine cleaning options, using this method followed by Silvo.' - John Rogers
This is quite an aggressive method, which can eat through the most stubborn of tarnishing. An item of silver should not be left to soak for a long period in this solution as in theory it would dissolve.
'Always use gloves and a cloth in a vessel filled with the solution and rub this over the item immediately upon submersion. When finished rinse with water.' - John Rogers
This technique is capable of breaking through the worst of tarnish and reach crevices that are otherwise hard to reach.
This method can leave a grey dulled appearance and may require another polish using a proprietary cleaner such as Silvo in order to gain a shine.
'This does eat at the silver surface and should not be done often as it would cause decoration and marks to become soft. I only really recommend this for truly problematic pieces. It is also particularly malodorous.' - John Rogers
Salt is the enemy of silver, which is why silver vessels designed for containing salt often have a glass liner or are gilt to prevent pitting. Salt should never be left in a silver vessel if not in use. Once it has been used during a meal, it should be rinsed thoroughly rather than left overnight.
When salt or a similar substance is left in contact with silver for too long, pitting of the surface occurs. This can become a permanent marring of the surface known as salt disease.
'Pitting can only be helped by a professional chemical cleaner and in terms of re-polishing, approach a a specific silver restorer.' - John Rogers
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