Sandblasting Abrasives

Get the nitty-gritty on sandblasting media

By Rodney Ruff, Technical writer/editor, freelance writer

In the "Star Trek" episode “Mudd’s Women,” frontier bride Eve McHuron cleaned the frying pans in the blowing sand on Rigel XII. On Earth, sandblasting uses a jet of compressed air or water to push a stream of sand across a surface to clean and abrade it.

Commercial sandblasting abrasives can clean cast iron and granite buildings or prepare metal surfaces for painting, enameling or galvanizing.

Media for sandblasters come in coarse, medium and fine grits; the higher the number, the finer the grit. Commercial sandblasting abrasives include walnut shells, coal slag, corn cobs, steel shot, glass beads and even baking soda, but three abrasives are the most common:

1. Silica sand is economical, but cuts slowly and can be reused only once or twice; fine grit sand often includes coarse and medium grains that can ruin finer materials.

2. Aluminum oxide cuts fast, is even-grained and is reusable, but generates static electricity, causing it to stick to etched glass, and can give its user a mild static shock.

3. Silicon carbide sandblast media has none of the drawbacks of either silica sand or aluminum oxide. Instead of wearing smooth as it blasts, it chips into smaller sharp-edged pieces. It also makes sparks when it hits, creating a flashlight effect to show the results of deep carving.

Get the right amount of sandblasting abrasives for your needs

Many sandblasting abrasives can be used over and over, great if you're a glass artisan on a tight budget. But if you make your living in the sandblasting business, you need lots of abrasives. Some companies accommodate both needs equally well.
Try: Abrasive Depot carries a full line of artisan, commercial and industrial sandblasting abrasives, with sandblaster media available in 32- and 64-ounce containers, as well as containers ranging from 3 to 50 pounds.

Deal with sellers who know the sandblasting business

Knowledgeable sellers of sandblasting abrasives offer a wide selection of sandblast media and help their customers select the right equipment.
Try: ToolsUSA offers a selection of sandblasting media–walnut shells, glass beads, garnet, aluminum oxide and silicon carbide–from 12 to 325 grit and a media separator to recover your abrasive after blasting. MetFin provides an extensive line of sandblasting abrasives for cleaning and other purposes, along with blasting equipment and the ability to customize systems for customer needs.

Strip for less with plastic sandblasting abrasives

Media for sandblasters isn't limited to metals, minerals or glass. Plastic abrasives provide a cheap, non-toxic alternative that's easy on both the blasted surface and the person running the blaster.
Try: Composition Materials makes five varieties of Plasti-Grit sandblasting abrasives for cleaning and coatings removal. Plasti-Grit is a custom-engineered, recyclable plastic sandblast abrasive that won’t damage finished surfaces.

Let the dust settle into a dust and fume collector

Sandblasting abrasives create a lot of dust, both from the abrasives themselves and the particles they abrade from the blasted surface. Unchecked, this dust can be anything from a minor irritant to a potential carcinogen.
Try: Farr Air Pollution Control’s Gold Series® cartridge dust and fume collector features high-entry cross-flow and specially treated, vertically arranged high-efficiency filters designed to trap dust particles as small as half a micron.

Dress right when sandblasting. Wear a safety helmet with goggles and ear covers, coveralls, work boots and forearm-length gloves.
Sandblast machine operators should also wear a standard air-breathing apparatus to deliver clean air, and not remove it until well away from the work area, as finer particles from sandblasting abrasives can hang in the air long after the job is done.