Young's Demonstrative Translation of Scientific Secrets eBook

This eBook from the Gutenberg Project consists of approximately 175 pages of information about Young's Demonstrative Translation of Scientific Secrets.

Young's Demonstrative Translation of Scientific Secrets eBook

This eBook from the Gutenberg Project consists of approximately 175 pages of information about Young's Demonstrative Translation of Scientific Secrets.

When the plating is as heavy as you wish, polish it with a mixture of chalk and alcohol, or of chalk alone, applied with a fine brush, or else a bit of chamois leather or rag.

If you wish to put on a very heavy coat of silver or gold, instead of using zinc alone as a battery, use the following, attach a piece of copper to one end of an iron wire about ten inches long, and a piece of zinc to the other end, and place both zinc and copper in contact with the article being silvered or gilded.

531.  Using French polish

There is a mode of using shell-lac varnish which is sometimes denominated the German, but more commonly the French mode.  It merits to be generally known, as the process is easy and economical, and the effect beautiful.  It has been much employed by cabinet and musical instrument makers, but is not yet so extensively practised as it merits to be.  The varnish is applied by means of what is called a rubber, made by rolling up a piece of thick woollen cloth, which has been torn off so as to have a soft, elastic edge.  The varnish, put into a narrow-mouthed bottle, is applied to the middle of the flat face of the rubber by laying the rubber on mouth of the bottle and quickly shaking the varnish at once, as the rubber will thus imbibe a sufficient quantity to varnish a considerable extent of surface.  The rubber is then enclosed in a soft linen cloth doubled, the remainder of the cloth being gathered together at the back of the rubber to form a handle to hold it by; and the face of the linen cloth must be moistened with a little raw linseed oil, which may either be coloured with alkanet root or not, applied with the finger to the middle of it.  The work to be varnished should be placed opposite to the light, in order that the effect of the polishing may be better seen, and a surface of from ten to eight feet square may be varnished at once.  The rubber must be quickly and lightly rubbed upon the surface of the article to be varnished, and the rubbing continued until the varnish becomes nearly dry.  The coil of woollen cloth must then be again wetted with the varnish, (no more oil need be applied to the surface of the linen cloth,) and the rubbing renewed till the varnish becomes nearly dry as before; a third coat must be applied in the same manner, then a fourth with a little oil, which must be followed by two others without oil, as before.  You proceed thus until the varnish has acquired some thickness, which will be after a few repetitions of the series.  Apply then a little alcohol to the inside of the linen cloth, and wet the coil with the varnish; after which, rub very quickly, lightly, and uniformly, over every part of the varnished surface, which will tend to make it even, and very much conduce to its polish.  The linen cloth must now be wetted with a little alcohol and oil, without varnish; and the varnished surface being rubbed over, with the precautions last mentioned, until it is nearly dry, the effect of the operation

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Young's Demonstrative Translation of Scientific Secrets from Project Gutenberg. Public domain.