When it comes to effectively eliminating rust and preparing a surface for paint or sealant, using the correct abrasive material will have a large impact on your final results. Two of the most popular abrasive types in use today are glass beads and garnet.

Both abrasives offer a number of advantages over other mediums like corn cob or walnut shells, but they are distinctly different from one another. 

Glass Bead Media

Glass blasting beads are growing in popularity for use with industrial sandblasting equipment today for a number of reasons. Glass bead media is a perfect option for steel, stone, wood, fiberglass, aluminum and concrete.

It is a fairly aggressive media that leaves behind less than 2% embedment and no dust. Crushed glass blasting media is also extremely cost effective, usually made from recycled bottles, and can generally be reused several times before replacing.

Glass beads are also silica free and inert, so they are environmentally friendly and will not leave any unwanted residue on your substrate. It is rated around a 6 on the Mohs Hardness scale, making it hard enough to cut through rust and leave a perfect anchor pattern for coating applications. 

Garnet Blasting Media

Blasting with garnet is another environmentally-friendly alternative to coal slag and other blasting medias. Garnet comes in a variety of sizes and is made from crushed Almandite or Andradite deposits. It can either come with rough edges or can be tumbled for more rounded edges. It rates a 7 to 8 on the Mohs scale.

Similar to glass, it is a low-dust and silica-free option which is safe for use around water. It is perfect for aluminum and fiberglass, enclosed tanks, dry docks and more.

Depending on the garnet blast media sizes being used, it can leave behind a profile anywhere from 1 to 4 mils. It is also recyclable and, with each use, the beads become more rounded which makes garnet for waterjet cutting another cost-friendly option.

Garnet sand abrasive can be used to prepare for industrial painting or powder coating without a problem. Many users report that garnet saves them a ton of time as well since it cuts deeper and more precisely than other common media choices. 

Blasting Media Comparison

Overall, both glass and garnet blasting media are known for their durability and environmental friendliness. Neither of them produces as much dust as coal or silica sand. Glass tends to be somewhat less expensive as it is made from recycled materials, but it is not quite as hard as garnet. Both are good options for concrete, aluminum and fiberglass substrates which need to be prepared for thick outer coatings. Of the two, garnet tends to have a longer lifespan due to its hardness and has extremely high density for faster cutting.