Friday, September 29, 2017

Silver Coating

Silver Coating Use Electroplating Method or Silver Plating

There are two method for silver coating on metal surface, first using electroplating or silver plating and second way using paint coating. Silver was one of the first metals to be electroplated using certain basic chemical electroplating, and the electroplating industry was thus founded in the 1840s. A great incentive to its development was the ability thereby to provide an attractive appearance and the hygienic handling of foodstuffs without the expense of making a whole article out of the costly metal. For some decades prior to the introduction of silver plating this difficulty had been overcome by the use of Shefield plate, a composite sheet metal made by rolling silver coating and copper coating together. Tableware and decorative articles were then made from the sandwich in such a way that only the silver was visible, actually this ware just silver coated. Electroplating was able quickly to take over this market and establish itself.

Silver raw material for silver coating can be found as silver plate or silver powder. Silver in powder form have dull color, but silver in metal form have bright color. Silver raw material for silver coating using electroplating method can use plate form, but for paint mixture must use powder form.

Silver metal
Silver Metal

Silver Powder

Silver coating using electroplating method has changed little since it was introduced. The solution is traditionally used at room temperature or only slightly warm, although this limits the permissible current density to between 5 and 10 A/ft2. As however, the silver atom is heavy, this corresponds to a rate of deposition of 0.0008 to 0.0016 in/h. The silver electroplate obtained from the simple double cyanide solution in milky white and Matt, but it is very smooth and soft. It can readily be color buffed or burnished to very high luster. Minor addition to the simple silver plating bath have long been known which limit the grain size of the deposit and produce a lustrous or bright silver coating. These are either organic sulfur compounds, typified by carbon di-sulfide, or small addition of other heavy metals such as lead or antimony. The increase in luster lessen the labor of polishing, but the main advantage is that the bright deposit is harder and more wear resistant.

For house hold and table articles, silver is usually applied to one of the copper alloys and predominantly to nickel silver alloy. Nickel silver is an alloy of copper, zinc and nickel, and is thus essentially a brass, bleached to a yellowish white color by the addition of nickel. A minimum 9% nickel is necessary to eliminate the brassy color, and 12 to 15% gives a white alloy.

Silver Coating Use Paint

We can coat metal surface with silver coat using a reflective bitumen paint, such as Alcolin Silver Coating that is used to protect bitumen membranes and equipment against UV degradation. This paint contain of aluminum pigments which can reflect UV light and enhance the durability of bituminous waterproofing equipment.

Many application of silver coating are using this method even the coating strength of coating is not as using electroplating method but still use because very simple way. Beside have good looking, metal also have longer stand to corrode.

Product Using Silver Coating

wheel coated by silver paint
Wheel with silver coating
this bolt and nut coated with silver coat
Bolt and Nut
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