Conservation and restoration of silver objects

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The conservation and recovery of silver objects is an activity dedicated to the preservation and protection of historical objects and personal value made of silver. When applied to cultural heritage, this activity is generally performed by conservators.

Historically, objects made of silver were created for religious, artistic, technical, and domestic use. Conservation and restoration measures seek to prevent and retard object damage and protect objects for future use. The prevention and removal of tarnish surfaces is a major concern of the conservator-restorers when dealing with silver objects.

Video Conservation and restoration of silver objects

Silver Usage

Silver is a precious metal that has been mined for use as early as 4000 BC. in Anatolia (Modern Turkey) Because silver is easily shaped and durable it has been used for many purposes including jewelry, tableware, ornaments, coins, musical instruments and film films. It is often used as a coating on other metals.

Maps Conservation and restoration of silver objects

Tarnish

All metals, other than pure gold, will naturally corrode when exposed to elements such as air. Relative humidity, moisture, and high air pollutants are common causes of corrosion in metals, including silver. Silver is known in the chemical world as a precious metal which means resistant to corrosion, but not completely. Whether silver plating or pure silver, the composite of the metal will stain when exposed to air and sulfur.

Sucking is a chemical reaction on metal surfaces (copper, brass, silver, etc.) and causes a corrosion coating. In the case of tarnish silver, silver joins the sulfur and forms a black sulphide (Ag2S) silver. The original silver surface can be restored if the silver sulphide layer is removed. In some metals, tarnish serves as a protective layer known as patina and is usually found on copper and bronze roofs, architectural elements, sculptures and bells.

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Collection care

Storage and handling

Proper handling, storage, and maintenance can help prevent damage to silver objects. The metal is best stored when stored in an even low humidity, ideally at a relative humidity of 40% or lower. Silver tends to rust easily when stored in a damp, moist place like a basement as it will speed up tarnishing. Some storage containers contain materials, such as wood, acid paper, rubber, and adhesives, which can be an off-gas corrosive material. Conservators wear nitrile gloves when handling silver to prevent oil, ammonia, and salt from skin due to corrosion on the surface.

Prevent interaction with sulfur gas

Gases and particles containing sulfur can damage the silver surface. These corrosive agents may come from air pollution, paints, textiles, bacterial byproducts, and other chemically treated or building materials or materials. When storing silver, the museum conservator wrapped silver in sulfur-free tissue paper and stored it in a sealed polyethylene bag. Activated charcoal is sometimes used to absorb sulfur by placing it in a bag but not in direct contact with the object. Likewise, the Silver Silver Fabric has also been used by museums to prevent desecration.

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Dismissal is the process of creating a hard durable finish on the surface of an object such as wood or metal. Polished silver is sometimes varnished to protect against stains and to prevent over-polishing. There are different types of resins used such as Acryloid B-72 and Incralac. If silver pieces are being displayed in the open, such as at home or museum exhibits, it is difficult to prevent corrosion from exposure to air. The surface layer will prevent or slow down tarnishing and is a service performed by professionals or conservators. One of the most widely used coatings is Agateen.

Lacquer is applied to surfaces that have been cleared with ethanol, acetone, or methyl ethyl ketone. Oil from human hands prevents laceration from sticking to silver. Agateen No. 27 (cellulose nitrate) and Paraloid B-72 are the most commonly used lacquers, but there are debates that use lak, cellulose nitrate or acrylic.

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The historic method of treating silver

The art of silverware, also known as silver, has been around for centuries. With the creation of handmade silver objects, the problem of cleaning and treating these items is a concern. Silversmiths will advise clients on how to properly treat their silver. Here are examples of instructions given by silver craftsmen in the 17th and 18th centuries.

1737 - "Clean now and then only with warm water and soap, with Spunge, then wash with clean water, and dry very well with a soft Linnen cloth, and store in a dry place, for moist with spoyle it ".

"... paste the flags and cups from topp to Bottome instead of crosswire, but Bason and patnes should be polished, not acrosse, and by noe use lime, sand, or salt "

Though dated, these instructions are very similar to current silver cleaning and polishing methods.

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Current practice

The following sections discuss different methods in which silver objects can be cleaned and polished. Some of the methods described below can cause damage to the silver surface, such as accelerated strokes or tarnishing. Conservator should be consulted if there is any question about the method below especially when dealing with archaeological, antique or sensitive objects.

Museum conservation practices - historic objects

Water sensitive objects are hidden in plastic wrap to avoid getting wet. The calcium carbonate dilute slurry (pharmaceutical grade) and deionized water are made and rubbed into the silver part with cotton cloth or cotton balls. It is recommended that the slurries are tested at the bottom or in silver areas that are not visible for roughness. If the slurry is too abrasive it will scratch the surface and increase the potential for future desecration. Polishes are applied with a soft cloth and polished in a circular motion.

Ethyl alcohol is sometimes added to the slurry mixture to help dry out the excess water. The slurry mixture is applied throughout the portion until it is completely polished. Dark spot spots sometimes lie on the surface and may need to be polished more than once for removal. Over polishing is a problem with silver and can cause damage to metal surfaces. After polishing, the silver objects are rinsed in deionized water and dried with cotton cloth.

After being cleaned and dried, silver wrapped in acid-free tissue paper and placed in a sealed plastic bag. 3M anti-tarnish strips are also placed in the bag to absorb the sulfur that may be in the air. The tissue paper is used as a buffer to prevent the silver surface from coming into contact with the anti-tarnish strip.

Waddings

Wadding is a fabric that has been impregnated with organic solvents. Since they contain solvents instead of water, they can be used to polish metal objects that can not be exposed to water. Polishing waddings will leave the abrasive particles behind and the residue can be removed using a soft brush or by rubbing the surface with a soft linen cloth.

Natural methods

The following sections include methods that use natural methods such as water and salt to clean the silver surface. Some methods use heat that may be harmful to silver tableware such as candlesticks or knife handles. Water trapped in the crevices of silver objects can speed up tarnishing.

Single Ingredient - Toothpaste is applied with a clean cloth as soft abrasive with a soft featherbrush and rinsed with water.

Boiling Water Immersion - A silver or piece item is placed into an aluminum pot and covered with water. A tablespoon of salt and baking soda is added and boiled for three minutes. After cooling, the silver is placed into a mixture of warm soapy water and cleaned with cotton cloth and then dried with a separate cotton cloth.

Bath Immersion - The glass toaster pan is coated with aluminum foil with the dull side facing down. Silver is placed on top of the foil and a liter of boiling water is poured over the cut with two tablespoons of baking soda. Silver wets for five minutes and dries with a clean cloth.

Chemical dips

A popular and quick method to polish silver is the use of chemical dips. Dips work by dissolving the stained silver surface at a very fast rate. Many dips are made of acid and other agents. The acid is highly corrosive and harmful to the silver surface and also to the user. Dips can be harmful to objects with closed surfaces such as candlesticks, trophies and pitchers with hollow components because chemicals can leak into hollow areas and can never be released. Unlike museum quality polishing, using calcium carbonate and ionized water slurries, dips are faster and cheaper. However, dips are more abrasive to the surface of silver, gold, and other metals. NOTE: Jeffrey Herman insists this method destroys silver - http://www.hermansilver.com/tarn-x.htm.

Laser Cleaning

Can be used. The above process will naturally lead to silver cleansing, which is passed through the laser to remove impurities and pollutants.

Plasma cleansing

Can be used. Plasma cleanser

Polishing the wheel

Wheel poles, also known as buffing wheels or polishing mops, use special electrical devices to physically remove stains from surfaces rather than chemically like calcium carbonate slurry or commercial dips.

Because silver is soft, its surface can be easily cut or scratched. The main buffing type used for silver, gold, and plated objects is the Canton flannel. The flannel is made of a very soft material and will not scratch the coated, lacquered, or other soft surfaces.

Along with the buffing wheel, certain compounds are used to help polish the material. The two main types of compounds used for silver and gold surfaces are red and blue compounds. Red, also known as rouge jewelry, polish without cutting action. The blue compound is a drying compound and is used with a non-fat wheel that also does not cut or scratch the surface.

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Museum conservation practices - Ancient objects

Archaeological silver objects are very sensitive to errors in planning or implementing conservation restoration. The fundamental problem associated with archaeological silver objects is fragility. Certain objects, such as fully mineralized, niello, or gil, are very problematic. When dealing with archaeological objects, reversible processes, such as the use of glue Paraloid B-72, are preferred over permanent treatments.

SILVER: THE CONSERVATORÃ,Â'S PERSPECTIVE, CONSERVATION INTERNATIONAL JOURNALISM Volume 9, Issue 1, January-March 2018: 81-90

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External links

• Silver Institute
• Wharton, G.; Maish, S. L.; Ginell, W. S. "Comparative Study of the Silver Cleaning Abrasives"
• "Silver, History, and Conservation", by R. van Langh-presentation
• Glenn Wharton: "Cleaning and Destruction of the Silver Museum"
• Jeffrey Herman "The Care of Silver"
• An approach to rusting silver archaeological conservation: plain of Crucinia, by A. Archi Olsoufieff, O. Colacicchi Alessandri, M. Ferretti
• CCI Silver Care and Tarnish removal
• V & amp; Silver conservation
• "Care and preservation of the history of silver", Clara Deck, Senior Conservator, The Henry Ford
• Silver preservation
• Clean silver with atmospheric pressure plasma
• Costa, V. The disadvantages of silver alloys and some aspects of their preservation
• Looking for silver
• Let Putz Silber ?, Stuttgart 2014.
• PLECO - an innovative electrolyte pencil for local cleaning of stained silver
• Wanhill, R. Identification, restoration and conservation of fragile silver archaeological

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Silver conservation video files

• Restructing Silver Items from Staffordshire Hoard
• Hoard Conservation Blog July 12: The Niello Project.
• Internal Prevention Protection Blog - Protecting Silver Collections.
• Science: "Silver Saver" - Nanotechnology Keeping Shine on Silver

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Reference

Source of the article : Wikipedia