|
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese|
FACTORY TECHNOLOGIES AT HOME - SIMPLE RECIPES
Mirrors. Simple recipes and tips
Directory / Factory technology at home - simple recipes Manufacturing of various mirrors, widely used both in home life and in astronomical, optical and electrical engineering practice, is produced mainly by depositing a thin layer of metallic silver on glass. Sometimes the mercury method was used, in which tin foil was fixed to the glass using mercury. The method of making mirrors using silvering, improved by Liebig, is based on the reduction of metallic silver from alkaline solutions of silver salts, called silver liquid, using various reducing agents, such as Rochelle salt, tartaric acid, milk sugar, grape sugar, invert sugar, formaldehyde and other substances. Silver nitrogen salt (lapis) is used as silver salt. Metallic silver can also be deposited on celluloid and thus produce flexible, unbreakable mirrors. Glass intended for making mirrors must be of good quality, smooth, without any flaws and well polished. Glass from old photographic plates can be successfully used to make small mirrors. The negative layer can be removed using a soda solution or by immersing the plates for 5-10 minutes in a solution consisting of 1 part formaldehyde, 1 part caustic soda and 50 parts water, after which the negative is rinsed with water and transferred to a solution consisting of 1 part saline acid, 1 part glycerin and 20 parts water. In this solution, the negative layer itself separates from the glass. To achieve good results, both the purity of the silvering solutions, salts and water used for the production, as well as the impeccable cleanliness of the glass itself, are important. Milk stains, noticeable when viewing the glass in an inclined position, are not washed off and can only be corrected by sanding with crocus. Before silvering, the glasses must be thoroughly washed, for which they are first placed in a weak solution of caustic soda in order to remove greasy and oily stains. Instead of caustic soda, you can use caustic potash or ordinary soda. After washing the glass in lye, rinse it well with clean water and spread it with fine powdered chalk or Vienna lime before use. Before use, the dried glass is thoroughly cleaned with a soft cloth and thoroughly washed with water, after which it is ready for silvering. To remove paint or varnish from old mirrors, immerse them in a caustic soda solution. To remove the silver layer from old mirrors, you can use either nitric acid or a mixture of nitric and hydrochloric acids (1 part nitric and 3 parts hydrochloric). To remove old pickup, you can also use the so-called chrome mixture. 400-500 g of chromium are dissolved in 10-12 g of water and 4-6 cm3 of concentrated sulfuric acid is added. The chrome mixture also removes paint, and can also be used to wash dishes used in mirror production. After using acids or chrome mixtures, the glass must be thoroughly rinsed with clean water. After washing the glass, as well as when silvering, you should not touch the glass with your hands, as your fingers leave greasy stains invisible to the eye, as a result of which the silver layer at the point of contact will not stick. Glass should be handled with clean cloths, rubber gloves or wooden clamps. The silvering process itself can be carried out in two ways: “face down” silvering (immersion in solution) and “face up” silvering. The latter method is usually used when silvering large glass surfaces. You can use any utensils for silvering that are not metal, namely: glass, earthenware, clay, papier-mâché cuvettes, etc. You can also use wooden or metal utensils, but you must first coat them with a layer of molten paraffin, asphalt or varnish . When immersing glass in a bath, it is not placed directly on the bottom of the bath, but on 3-4 glass pieces placed in the corners of the bath, or a block is glued to the glass using wax or tar, the ends of which should protrude beyond the edges of the glass. When lowering the glass into the bath, the block lingers on the walls of the bath, leaving a gap of 10-12 mm between the bottom of the bath and the glass. Then the glass is lowered into the bath and the solution is poured in such an amount that it covers the bottom of the bath, the bottom side of the glass and reaches almost the top side of the glass. When using this method, you need to make sure that there are no air bubbles under the glass and that the solution does not flood the top side of the glass. We recommend that you set once and for all the amount of liquid required for a given glass size. For small glasses, you can also use suction cups in the form of cups and a rubber ring. When silvering the glass, the glass is held by this glass. When silvering by pouring, a strip of wax paper is glued to the glass in the form of a side using wax or paraffin. You can also make a rim around the glass using wax, clay, paraffin or other materials. When silvering large glasses, special overhead, strictly horizontal tables are used. The table is equipped with a groove into which excess silver liquid flows. When using the hot silvering method, overhead tables are equipped with a device for heating the upper side of the table with steam. After silvering, the mirrors are thoroughly washed in distilled water, after which they are placed in a vertical position to dry. After drying, the silver layer is coated, in order to protect it from mechanical damage and atmospheric influences, with asphalt or dammar varnish or oil paint (red lead diluted in linseed oil). If special strength is required, then the silver layer is galvanically coated with a layer of copper and then varnished. It should be noted that serious attention should be paid to washing finished mirrors, since insufficient washing can cause stains to appear on the mirror. Moving on to the description of methods for silvering mirrors, it should be noted that all work must be carried out extremely carefully, patiently, paying special attention to the cleanliness of the dishes and the chemical materials used. During experimental work, you should pay attention to how the temperature of the room, glass, solutions, room humidity and a number of other circumstances affect the glass silvering process. When silvering by immersion, it is useful to first immerse the glass in water heated to 30-40 °C. Author: Korolev V.A.
▪ Cement for gluing glass plates ▪ Flame retardant yarn and cotton
Machine for thinning flowers in gardens
02.05.2024 Advanced Infrared Microscope
02.05.2024 Air trap for insects
01.05.2024
▪ Multi-protocol wireless microcontrollers STM32WB55 ▪ Fujifilm returns to the black and white film market
▪ section of the site Fundamentals of safe life (OBZhD). Article selection ▪ article Crystal dream of my childhood. Popular expression ▪ article Which language does not have the words yes and no? Detailed answer ▪ article Picket node. Travel Tips ▪ article Copper. Encyclopedia of radio electronics and electrical engineering
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua |
We recommend interesting articles Section 
See other articles Section 
Latest news of science and technology, new electronics:
All languages of this page