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Glass finishing technology

Hardening glasses

It is known that glasses often burst, at other times, even without any visible reason, but in most cases because of a sharp change in temperature, when, for example, hot water is poured into a cool glass or vice versa. In view of this, we consider it not unhelpful to cite the following unsophisticated method of quenching, which has been repeatedly tested, with which the glasses can be given the ability to withstand sharp changes in temperature perfectly. For this purpose, glasses, individually wrapped in straw, are placed in a metal (fish) pot, in which water is poured at room temperature and put on the stove so that the water gradually boils. Then, after holding the glasses in boiling water for 5-6 hours, the boiler is removed from the flame and covered with some kind of blanket so that the water cools down little by little. When the water temperature equals room temperature, the glasses can be considered already fully tempered, and they also very well withstand, without breaking, the sharp transitions from hot water to cold or back.


Pencils for the message on glass, porcelain and metal

Pencils of this kind can be prepared from the following composition: 4 elements by weight of spermaceti, 3 elements of fat and 2 elements of wax. Then, depending on what color the pencils want, 6 parts of dry paint are added to this mixture. The mass produced in this way remains to be molded in the form of sticks, and the pencils are ready. They are equally good at writing notes and act without spoiling the glass, porcelain or metal itself.


Casting Mat on Glass

To make the window glass opaque, you should dissolve the yellow "special" wax in turpentine and add a little desiccant (drying) to this mixture so that it dries faster. This mixture is lubricated with window glass, evenly smoothing it with a cotton cloth swab. If you want to get a colored surface, you can add some dry paint in the powder to the mixture.


Labels on glass

In some cases, it may be useful to replace paper labels pasted on glass bottles and cans, and use matte inscriptions directly on the glass. Such labels-labels are more convenient not only in the sense that they are stronger than paper ones, but also to replace them is not so easy. As a consequence, we consider it not unhelpful to cite the subsequent composition recommended for etching frosted labels and labels on glass. 36 g of sodium fluoride, 7 g of potassium sulfate are dissolved in 0.5 l of water. Another solution is prepared immediately: 14 g of zinc chloride and 65 g of hydrochloric acid are also added in 0.5 l of water. When used, both data of the solution are mixed in equal proportions, also using a soft pen or a fine brush, draw letters on the glass. After half an hour, a frosted label made by brush or pen appears on the glass.


Cutting glass tubes

Wrap the room of the tube in which they want to cut it, with a wide enough strip of paper of such length that it wraps the tube several times, also glue the ends, and attention should be paid to ensure that the edge of the paper exactly matches the place of the intended cut. Next to this piece of paper, another strip of paper is glued in exactly the same way so that between them there is a very narrow space of naked glass of uniform width around the circumference, along which it is also forced to pass a cut. Strips before wrapping, it is useful to slightly moisten. Then a narrow space is placed between the pieces of paper above the fire (a kerosene lamp cylinder or an alcohol burner). The tube is rotated above the flame until the space of the unprotected glass between the pieces of paper does not warm up sufficiently, so that a drop of cold water dropped onto this place causes a neat and smooth cut. The papers wrapping the glass tube prevent the penetration of heat to the surfaces covered by them also because the flame acts especially intensively on the unprotected strip of glass. Before you send the flame to the glass tube, it is necessary to dry the paper, wrapped on the tube, because the dampness on the glass can lead to rupture it on the wrong lines.


Glass drilling

A thin steel drill, heated to white, hardened in mercury or a piece of sealing wax is also hardened. Then prepare a saturated solution of camphor in turpentine, moisten with it a drill, mounted on a brace, also hastily drilled glass, which is wetted at the drilling point with the said solution. In this way, it is possible to drill a glass 1 cm thick in less than one minute.

In order to drill a hole in the glass, we recommend that you take a three-sided file, lower it into the turpentine and carefully drill the hole.

You can also drill glass on a lathe with a copper rod, lubricating it with oil and sprinkling it with sandpaper. Special attention should be paid to the hole, at what time the drilling process comes to an end, only the final thinned layer remains, as if the glass could easily crack.


Glass stamping

For this purpose, a vapor solution is prepared - one of 100 g of water, 12 g of sodium fluoride and 2 g of potassium fluoride, but the other - of 100 g of water, 20 g of hydrochloric acid and 5 g of zinc chloride. Equal parts of each solution are mixed before use and also applied with a rubber stamp on the glass, which should be well wiped beforehand.