Identifier: modelmakinginclu01yate (find matches)
Title: Model making; including workshop practice, design and construction of models, a practical treatise for the amateur and professional mechanic..
Year: 1919 (1910s)
Authors: Yates, Raymond F. (Raymond Francis), 1895- ed
Subjects: Mechanical models
Publisher: New York, The Norman W. Henley publishing company
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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uctionand manipulation of a small but practical outfit, whichwill enable the mechanic to properly plate and finish hismachine or instrument parts. While it is not the purpose of the author to give alengthy treatise on the theory of electro-deposition, abrief outline of the fundamental principles involved willbe given, as an elementary understanding of the theoryof any process or operation about to be performed in-variably proves helpful and advantageous in actualpractice*. Pure water is a very poor conductor of the electriccurrent, but if a small quantity of table salt (sodiumchloride) is dissolved in it, it at once becomes a com-paratively good conductor of electricity, and in this stateis technically known as an electrolyte. If we immersetwo electrodes in such a solution and pass a current be- 126 Electro-Plating 127 tween tliem, it will tend to decompose the table salt intoits constituent elements, i.e., sodium and chlorine. Theatoms of sodium will accumulate at the ne2:ative elec-
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Fig. 88—A glass storage battery jar used as an electro-plating vat trode or cathode and the chlorine will be attracted bythe positive electrode or anode. This is exacth^ Avhat happens in the process of electro-plating. For an illustration, we will assume that we areplating with nickel. In place of the sodium chloride,nickel-ammonium sulphate would be dissolved in thewater, and upon passing an electric current through such 128 Model Engineering a solntion Ave would find that tlie negative electrodewould soon become covered with a thin deposit of metal-lic nickel owing to the decomposing action of the cur-rent. If we take the negative electrode out and substi-tute it with articles to be plated, we will find that thearticles will undergo the same process and a deposit ofnickel will form on them. If we wish to plate with cop-per, copper sulphate should be substituted for the nickel-ammonium sulphate, etc. In many cases, where there are but a few small arti-cles to be electro-plated, a s

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