Etching and Acid washing of glass

  Describe etching on glass.

Ans.          Transparent glasses are etched on controlled area or on entire area depending upon the need. On etching, this area becomes opaque like ground glass. Thus a desired design effect is given to the glass panes and these are used in windows, shutters, partition panels or on tabletops.

                   

There are two ways of etching –

i] With gelatin paper and sand blasting-

            A thick self-adhesive gelatin paper is pasted on the glass. The paper, where etching is to be done, is cut & removed. After this, fine sand particles are bombarded on the exposed glass portion with sand blasting gun. The glass is, then cleaned by soap water to remove the gelatin paper and kept ready for dispatch.

           

ii] With gelatin wax and mild acids (like hydrofluoric acid) –

Gelatin wax is coated on the glass with a filler blade. The wax, in the area where etching is to be done, is removed by a sharp & pointed knife. Acid is applied on the exposed glass. The acid reacts with glass creating etched surface. Then the glass is cleaned.

            With Hydrofluoric acid, the surface etched is like the sand blasting. Before the acid reacts with glass, surface textures of different types can also be attained by pressing the area with different materials like cloth or sponge or sticks etc. . A combination of these textures with different profiles can be made giving abstract shapes or artistic figures. Such glasses are called to be ‘acid washed’.