When it comes to effectively removing rust and preparing a surface for paint or sealant, using the right abrasive material will have a big impact on the end result. The two most commonly used abrasive materials today are glass beads and garnet.
These two abrasives offer many advantages over other media such as corn cobs or walnut shells, but they are distinctly different from one another.
Glass Bead Media
Glass blasting beads are increasingly common in today's industrial blasting equipment for a number of reasons.
It is a fairly aggressive media that leaves less than 2% residue and is dust-free. Crushed glass blasting media is also very cost-effective, often made from recycled bottles, and can often be reused several times before being replaced.
Glass beads contain no silica and are inert, so they are environmentally friendly and will not leave any unwanted residue on the substrate.
With a Mohs hardness of approximately 6, it is hard enough to penetrate rust and leave a perfect anchoring pattern for coating applications.
Using garnet blasting is another environmentally friendly alternative to cinders and other blasting media. Garnet comes in a variety of sizes and is made from crushed almandine or andradite mineral deposits. It can have a rough edge or be tumbled for a more rounded edge. It has a Mohs hardness of 7 to 8.
Similar to glass, it is a low-dust, silicone-free option that is safe to use near water. It is ideal for aluminum and fiberglass, closed tanks, dry docks, and more.
Depending on the size of the garnet blasting media used, it can leave a 1 to 4 mil profile. It is also recyclable, and the beads become more rounded after each use, making garnet another affordable option for waterjet cutting.
Garnet sand abrasives can be used in industrial painting or powder coating preparation without any problems. Many users report that garnet sand abrasives also save them a lot of time because it cuts deeper and more precisely than other common media.
Sandblasting Media Comparison
Overall, both glass and garnet sandblasting 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 a bit cheaper because it is made from recycled materials, but it is not as hard as garnet. Both are good choices for concrete, aluminum, and fiberglass substrates that need to be prepared for a thick outer coating. Of the two, garnet tends to have a longer life due to its hardness and has an extremely high density, allowing it to be cut faster.
