What Is the Safest Abrasive for Glass Etching?

Etching Safety

• Glass etching is a fairly safe art and craft, but you do need to follow all recommended safety practices. The best way to protect your skin and your eyes is to wear gloves and etch your glass in a self-contained blasting cabinet with a well-maintained dust collector, where the cabinet’s window protects your face and eyes. For blasting outdoors or in a blast room, wear an air-supplied blasting hood and gloves. Protect your lungs whenever you are exposed to dust with a dual-cartridge respirator. Wear earplugs or other hearing protection.

Avoid Using Sand

• Sand meets basic criteria for effectiveness. It’s hard enough -- as hard as glass, which is primarily made of sand – and the particles are rough-edged and sharp. But the dust from sand is extremely hazardous and can cause the fatal lung disease silicosis. While glass is hard, it’s only about half the hardness of silicon carbide. Particles that get dull lose their sharpness quickly and can’t be reused too many times. Sand also doesn’t come in grit sizes fine enough for most etching work.

Silicon Carbide

• One of the two safest glass-etching abrasives, silicon carbide is found very rarely in nature as the mineral moissanite. This is the stuff used to make plates in bulletproof vests and diamond-like jewelry. Because it’s so hard -- almost as hard as a diamond -- it cuts very fast. It is also almost endlessly recyclable, more so than any other abrasive. Silicon carbide -- also known as carborundum -- generates no free silica during blasting because it splits apart to generate equally sharp smaller particles. What little dust it generates is more nuisance than health hazard. The Professional Glass Consultants website argues that silicon carbide is more cost-effective than aluminum oxide, the most popular glass abrasive, if you consider cost per hour instead of cost per pound.

Aluminum Oxide

• Almost as hard as silicon carbide, aluminum oxide also cuts fast and is very effective for etching glass. It can be reused and comes in a very wide range of grit sizes, making it suitable for many purposes including executing complex designs. The dust it generates is merely a nuisance, not a health hazard. A key drawback with aluminum oxide is the static electricity it generates, which can cause “static shock” and also obscure the in-progress design. Because of static electricity, aluminum oxide dust clings to the glass, so it’s hard to see the surface clearly.