Engraving and sandblasting glass are two glassworking techniques that allow artisans to create a frosted or carved look on glass surfaces. These are techniques often used on window and door panes, decorative art glass, glass beads, glass tiles and glass trophies and plaques. Methods for engraving and sandblasting glass are as varied as the art projects themselves. Small-scale tabletop sandblasters and hand-held engraving tools or acid baths are used for small projects, while industrial-sized blasting cabinets and pneumatic engraving tools are used for larger projects. The overall technique and approach, however, remains the same regardless of the project's scale.
Carefully clean the glass to be sandblasted to ensure there is no dust or dirt on the surface, and apply choice of etch-resistant material firmly to the glass surface, if desired. Etch-resistant material is a self-adhesive plastic, rubber or resin pattern or decal applied to the surface of glass that will protect the base glass from the etching media.
Secure the glass inside the blasting cabinet. If the project is large-scale, use a blasting cabinet that has adjustable stands and securing mechanisms for holding the glass firmly in place during the blasting process. If you are sandblasting a small object using a small, tabletop blasting cabinet, it is easiest to hold the glass in your hand while wearing heavy duty industrial strength rubber gloves.
Put on your protective eye wear and dust mask or respirator and load your sandblasting media into the media hopper portion of your sandblasting cabinet. A variety of sandblasting media is available, ranging from fine black sand to walnut shells. The media you select will be based on the thickness of the glass you are using and the depth of sandblasting you are trying to achieve.
Attach an air compressor to your sandblasting cabinet and turn it on. The strength of compression will be determined by the depth of blasting you are trying to achieve and the thickness of glass you are using. The information that comes with your blasting medium will provide direction on strength of air compression needed to achieve desired results.
If you are working with a large sandblasting cabinet, place your hands in the attached glove compartments of the cabinet and grasp the blasting hose and pen. In slow, even spray strokes, apply the blasting material to your glass, working from the upper left corner and moving from side to side. If you are using a tabletop sandblasting cabinet, the process will be the same, only the glass object will be held in your gloved hand during the blasting process.
When you have completely sandblasted your glass piece, turn off your air compressor and insert a shop vac to suck up all blasting media and return it to the hopper. When the dust is settled, gently pull a small section of blast resist material away from the glass surface to gauge the depth of the sandblasting. If the blast is not deep enough, replace the resist and repeat the sandblasting process until desired effect is achieved.
Remove all resist. Clean glass with a commercial glass cleaner and allow to air dry.
Carefully clean the glass to be engraved to ensure there is no dust or dirt on the surface. If you are using a stencil or pattern, secure it to the surface of the glass. If you are engraving freehand, steady your wrist in a comfortable position over your glass piece and don your face mask and protective eye wear.
Select an appropriate engraving tip for your engraving pen. The thinner the tip, the finer the engraving.
In smooth and continuous strokes, engrave your glass by drawing or writing freehand, or by following your pattern outline. Lift the engraving pen at the end of each stoke.
Dust your engraved piece with a clean, dry paintbrush to remove glass particles. Examine the work to see if any portion needs heavier engraving and perform any necessary touch-up strokes. Once project is complete, clean glass object with a commercial glass cleaner and allow it to air dry.
Large-scale computer-aided etching can also be achieved through use of industrial-level engraving machines. Additionally, commercial acid etching products can help you create an etched look and feel without investing in heavy or expensive equipment.
Glass particles and sandblasting medium are often very fine and can easily get into your eyes and lungs. Be sure to wear protective eye wear and a dust mask or respirator when sandblasting and engraving glass.