This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1895 Excerpt: ...are to be left silvered, it will be necessary to apply certain preparations to the parts to be protected. For this purpose many preparations are used. A solution of gum copal or mastic may be ap plied with a camel-hair brush; but, unless these varnishes are tolerably thick, they are apt to run. The composition ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1895 Excerpt: ...are to be left silvered, it will be necessary to apply certain preparations to the parts to be protected. For this purpose many preparations are used. A solution of gum copal or mastic may be ap plied with a camel-hair brush; but, unless these varnishes are tolerably thick, they are apt to run. The composition described at page 59 may be used for this purpose, but it will not be safe to use it in hot solutions. In some cases a strong solution of shellac in alcohol may be used to cover certain parts of an article which require protection. 61. In gilding chains, brooches, pins, rings, and other articles which have been repaired, i.e., hard soldered, sometimes it is found that the gold will not deposit freely upon the soldered parts; when such is the case, a little extra scratch-brushing applied to the part will assist the operation greatly, and I have sometimes found that dry scratch-brushing for an instant--that is, without the stream of beer usually employed--renders the surface a better and more uniform conductor, and consequently it will more readily receive the deposit. In fact, dry scratch-brushing is very useful in many cases in which it is desirable to impart an artificial coating of brass upon an article to which silver or gold will not readily adhere. In scratch-brushing without the employment of beer, or some other liquid, however, great care must be taken not to continue the operation too long, as the minute particles of metal given off by the scratch-brush would be likely to prove prejudicial to the health of the operator were he to inhale them to any great extent. 62. In gilding or silvering steel articles by the processes described in paragraph 55, it will be necessary to clean them with a little diluted potash in order to re, move grease; and ...
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Add this copy of Electro-Metallurgy Practically Treated to cart. $19.72, new condition, Sold by Ingram Customer Returns Center rated 5.0 out of 5 stars, ships from NV, USA, published 2022 by Legare Street Press.
Add this copy of Electro-Metallurgy Practically Treated to cart. $29.16, new condition, Sold by Ingram Customer Returns Center rated 5.0 out of 5 stars, ships from NV, USA, published 2022 by Legare Street Press.
