The Types of Sand for Sandblasting

Sandblasting is done with a variety of cutting media. Materials other than sand used widely include aluminum oxide, silicon carbide, crushed walnut shells and glass beads. Brown sand and white crystal silica sand are the sands most often used. Silica sand is most widely available commercially. There are health hazards associated with inhaling dust produced by sandblasting with silica sand.

Size of Particles

Sand is rated by how coarse or fine it is. Grit, a measure of texture, is calculated by running sand through a sieve. The size of the sieve is called its mesh. Coarse grit cuts faster and is more useful for blasting rust and other crude work. Fine grit leaves a smoother finish. Grits of 30 to 80 are used for blasting wood or stone. Grits of 100 to 150 are used to etch windows, 150 to 220 for glassware and trophies, and 220 to 400 for micro-blasting. Finer grits generally cost more than coarse grits.

Shape of Particles

Some sand, such as that found along rivers, has a round edge, better for producing polished surfaces.
Crushed rock usually yields sand that is angular; it has triangular-shaped edges, better for raw cutting.

Beach Sand

You can use raw beach sand for sandblasting. One drawback is that beach sand includes salt that can deposit on the metal you are sanding and leave it more susceptible to rust after you paint it. You should wash beach sand to remove the salt. You should also be aware that the quality of beach sand can vary over the course of a few miles. Beach sand has a tendency to break down, so it's often not good for repeated use.

Silica Sand

This is the sand most often used, largely because it is cheap and widely available. Its drawback is that it breaks up quickly and creates dust, which can be harmful to the operator. The silica is usually in the form of minute particles of quartz.

Other Sands

You can use almost any sand for sandblasting. Most sand is composed of silica. Tropical sands and coastal sands are often made of limestone. Other sands are made of gypsum, limestone, basalt and other minerals, including obsidian, which yields black sand. Generally speaking, darker sands are harder than lighter sands.

Warning

Prolonged breathing of the dust produced by sandblasting with silica sand can lead to a serious lung disease called silicosis, according to dalefield.com. Inhaling particles of silicon in the dust can scar an operator's lungs, causing shortness of breath, a bluish tint to the skin and fever. When blasting with silicon sand, always wear a mask or other device to filter the dust.

References

• Abrasives
• Sandblaster equipment
• Sandblasting by Daryl Anderson

Resources

• Sand Blaster