Acid etching is a process that uses a strong acid to cut into another substance. It is used for both industrial and artistic purposes. For example, etching can be used to prepare flooring like cement for painting or refinishing, while artists use it to create detailed pictures on metal or glass.

Acid-etched glass has a distinctive, uniformly smooth and satin-like appearance. Acid-etched glass admits light while providing softening and vision control.

Origin of Acid-etched glass

During the middle ages, acid glass-etching was somehow clouded with controversy since its acid medium, hydrofluoric acid, caused too much of a health risk to the artisans. In fact the acid was so potent that users were found to have been poisoned even by its mere fumes. Accidents most often happened where a skin contact with the acid dissolved into the tissues, which later resulted in mutilation or loss of the artisan’s fingers. As a result, acid etched glass craftsmanship lacked refinement and thus lost its luster as an art collection.

Now, there are etching tools such as swivel knives, pick knives, adhesive masks aside from the squeegee which makes it possible for an ordinary person to work on acid glass-etching.

Acid-Etching Glass production

Acid etched glass is produced by acid etching one side of float glass. Etched glass is created by cutting a design stencil that is made of an abrasive resistant material, such as vinyl or rubber. The resulting stencil is called a resist. The resist is then secured onto the glass to be etched. A blaster gun, powered by an air compressor, is used to bombard the glass with the abrasive. Every part of the glass that is not covered by the resist will take the frosted effect while the parts protected by the resist will remain clear, thus producing a piece of etched glass.

Etching glass - Hydrofluoric acid

Glass is etched by hydrofluoric acid, or by hydrofluoric acid gas. The gaseous acid has the property of producing a surface which resembles ground glass in its appearance; the liquid acid produces clear etching. Etching glass, therefore, consists of 2 distinct branches. First, the production of a dull image on a clear surface (when the gas is used) and second, the production of a clear image on a surface previously ground or dulled by means of the liquid acid.

The glass plate to be etched is cleaned and gently warmed until hot enough to melt wax. The surface is then covered with an equable layer of white wax, by rubbing the wax over it. When cold, the design is cut out of the wax with a graver. A shallow leaden trough, about the size of the plate (but a trifle smaller) is obtained, into which is placed a small quantity of finely - powdered fluorspar. This must be weighed and then gently sifted over the bottom of the trough. To every 2 parts by weight of fluorspar add 3 of good oil of vitriol. Stir quickly with a wooden stick, and place on the hob or other warm place. Vapour will soon rise.

Now the trough is removed and covered over with the waxed and graved plate, wax side downwards. In a very short time, the acid will have etched the bare portions of the glass. When sufficiently etched, remove the wax by melting. To prepare the liquid acid for clear etching, place 2 parts fluorspar and 3 of sulphuric acid in a leaden retort, the tube of which must dip into a leaden bottle half - filled with water.

Apply heat to the retort as long as the water will absorb the fames generated. If a ground glass be prepared with wax, as above, and a ledge of wax or putty be made round it, on pouring the liquid acid on the plate, clear lines on the dull ground will result; or a "flashed" colored glass may, by the same means, a colorless picture on a colored ground can be done. The sheets of clear glass may themselves be dulled by exposing them, without previously waxing, to the fumes of the acid gas.

Applications

Acid etched glass is perfect for both interior and exterior applications. Architecture and construction, like in houses, restaurants, hotels, commercial buildings, etc. They are found in many residential applications such as home decoration like furniture components. Some of the suggested applications are:
 
•    Interior partitions
•    Railings
•    Shelves
•    Shower and bath enclosures
•    Doors andwindows
•    Glass walls
•    Kitchens
•    Interior and exterior doors