Cleaning mirrors, crystal and porcelain.
You can use any of the glass cleaning liquids available on the market to clean the mirrors, especially automotive. When preparing glass washing mixtures yourself, containing substances in the form of powders, pay attention to their careful sieving and grinding, as slightly larger grains may scratch the glass. The greatest care should be taken when washing crystal glass, which is very soft.
A very good cleaning and polishing agent for all types of glasses is magnesium carbonate (magnesium) or calcium carbonate, which should be mixed with water, with denatured alcohol or gasoline to make a slurry with the consistency of thin cream. Flannel should be used to rub the glass with this suspension, cotton wool or soft rind, called chamois. Cotton or linen canvas easily scratches glass. If gasoline or denatured alcohol was used to make the suspension, do not wash the glass with water afterwards, but wipe dry, changing the flannel or chamois leather.
When washing the windows of a flat or a car in winter, it is worth protecting them against freezing with the mixture 50 cm3 of glycerin, 50 cm3 of water i 1000 cm3 denatured. Wipe dry glass with this mixture, so that a very thin layer of liquid remains on it. Moisten the glass, which is already icy, abundantly with the mixture, and when the ice melts, wipe dry and reapply a thin layer of liquid.
Crystal dishes should not be washed with water with detergents, as they can lose their beautiful shine. For cleaning, use water with the addition of a small amount of sodium carbonate (soda). In order to improve the shine of the crystals, it is necessary to etch them for a few minutes (no longer than 10 minutes) in 0.5% aqueous solution of nitric or acetic acid. Such solutions are obtained by diluting nitric acid to the ratio of 1:100 or 10 percent vinegar in the ratio 1:20.
The lenses of optical instruments must not be washed with any agents. They can only be cleaned with a chamois leather after a slight misting by blowing. Camera lenses cannot even be rubbed with a chamois leather, only cleaning with a soft brush is allowed!
Porcelain is usually covered with glaze of considerable hardness, so it does not require such caution when washing, like crystal glass. Here again, however, you should beware of the use of scouring agents with coarse grains, which scratch the enamel and wear off surface decorations. Gold-plated places are especially sensitive. For washing gilt porcelain, use water with a little sodium carbonate, a very soft brush or a flannel cloth.. Wipe only with a soft cloth, never with a linen cloth!