Care of Silver 

Most silver plated cutlery and hollow ware is marked ‘E.P.N.S.’ – the abbreviation for ‘Electro-Plated Nickel-Silver’. ‘Nickel-Silver’ identifies the base metal as a copper-zinc-nickel alloy; it contains no silver but, because its nickel content imparts a colour more akin to silver than brass, it has always been known as ‘nickel-silver’. ‘Electro-plated’ in this context means that the articles are electro-plated with silver – the first metal to be used extensively in electro-plating. In many countries including USA, nickel silver is not used, but brass is used instead.  Silver thickness is normally quoted in ‘microns’. (One micron is one thousandth of a millimeter).

Stainless steel cutlery can be silver plated. Hollow ware can also be sometimes silver plated, in which case it may be marked ‘E.P.S.S.’.

Tarnish

Silver, being a noble metal, is highly resistant to corrosion, but it can be tarnished by sulphides that are always present to some extent in the atmosphere and in many foods, green vegetables and eggs being the most potent. Tarnish consists of a superficial film of silver sulphides. Initially it is a light gold colour, but, with prolonged exposure to sulphides, it can develop into a blue-black discolouration.  Tarnish is not usually a problem in hotels and restaurants where items are in constant use and are washed and dried regularly.

Sulphides in the atmosphere originate mainly from combustion of gas oil, coke, wood etc. and from living creatures. To avoid the need for frequent cleaning, it is best to store silver, when not in use, in a cupboard or drawer. To avoid tarnishing by food, rinse it off the cutlery as soon as convenient. Tarnish resisting papers and cloths are available to store silver, which certainly reduce the rate of tarnishing.

Tarnish Removal

Four methods of detarnishing silver are available: polishing powders or pastes, chemical dip solutions, electrolytic methods and ball burnishing.

Polishing Powders and Pastes

Only those sold specifically for silver should be used; cleaners intended for chromium plate, stainless steel etc will scratch silver. Always apply the cleaner with a soft cloth or sponge – either of which should be thoroughly and freshly washed to eliminate any abrasive dust particles, which could cause scratching.

Some cleaners that are available in paste or emulsion form, not only remove tarnish but contain tarnish inhibitors. Such products are particularly useful for silver plated hollow ware (being handled, washed and wiped less frequently than cutlery, the inhibiting effect lasts longer).

Over zealous pressure when cleaning with powders may remove significant amounts of silver, which ultimately will wear through the plate completely.

Chemical Dip Solutions (Often referred to as silver dip)

Provide a rapid, less arduous method of detarnishing, especially on heavily embossed designs whose crevices are difficult to clean with silver powders. These dip solutions convert the film of tarnish (silver sulphides) back to silver by removing the sulphides without removing any silver. However, the following precautions must be taken:

1. Never leave silver plated cutlery in the dip solution for more than 10 seconds.
2. Do not use dip solutions to remove very heavy tarnish. They will convert the silver sulphides to silver but, because heavy tarnish is thicker, the surface of the restored silver may have a matt finish.
3. Dip solutions can stain or even etch stainless steel knife blades. Any drops that fall onto blades or other stainless steel equipment should be rinsed off immediately.

Electrolytic Methods

Tarnish can be removed from silver by immersing it in a hot solution of washing soda of about 30 grams per 5 litres whilst the silver cutlery or silver plated hollow ware is in contact with aluminium.

Proprietary kits are available but the process can be carried out on a DIY basis in a plastic bowl with a sheet of aluminium foil laid in the bottom so that the cutlery is in contact with the foil. When the foil eventually darkens and becomes brittle, it becomes ineffective and needs replacing.

As in the case of chemical dip solutions, the process is not suitable for use on very heavily tarnished silver upon which it can produce a dull white finish.

Ball Burnishing

This is a bulk process for use in large catering establishments. The silver cutlery is placed in a rotating drum containing steel ball bearings, water and a corrosion inhibitor to prevent the steel balls from rusting. Its prime purpose is to brighten and harden the surface so that it becomes more resistant to scratching and wear. However, it will also remove light to moderate tarnish, except in the crevices of heavily patterned pieces.

Despite the apparent severity of the process, it does not wear off the silver if carried out under intelligent supervision and in accordance with the machine supplier’s instructions. Problems likely to occur are:

Entanglement of fork prongs which may cause some to bend. This can be avoided by positioning the compartment separators closer together so that the forks stay orientated across the barrel.

A matt scratched finish, caused by having insufficient water in the burnisher – this can occur as a result of leakage if the machine’s lid has not been adequately tightened or if its seal is defective.

Developments of grooves on the sides of vessels such as tea post. This is caused by the compartment separators being too close together, thus allowing steel balls to become entrapped between the separators and the sides of the vessel – to the detriment of the latter. Compartment widths should be adjusted to suit the width of vessel being burnished.

Silver plated hollow ware can be damaged if large heavy items are burnished in the same compartment.

Silver cutlery should be washed and dried thoroughly after cleaning.


Reproduced from the CATRA website