Loose grain abrasives are widely used throughout the finishing industry for blasting applications (prep for coatings) primarily, but can also be used as an additive to a vibratory deburring process to accelerate the cutting action. Some common materials include:
- Aluminum oxide: This type is very popular and is used in many different items other than finishing (e.g. anti-skid surfaces, laminate flooring (that’s why it is so durable) and, of course, sandpaper). Sizing ranges from tumbling chips to fine powder abrasives in brown or white.
- Glass beads: These are another popular product for finishing and are used in many different applications. The peening action provides minimal stress relief, along with a very nice and even satin finish. Automotive engine parts and aluminum or stainless final surface appearances use these, as do highway line paints for reflectivity.
- Silicon carbide: These loose grain abrasives are more specialized per application, but brazing/soldering applications may need to use this. Vibratory tumbling media in silicon carbide do so for the same reason.
- Corn cob maize: 3 standard sizes; can be treated for polishing processes.
- Walnut shell, crushed: 3 standard sizes (fine, medium and coarse); light or fine deburring and the main product for your red or green treated shells (polish)
- Plastic blasting media: Crushed plastic in different MOL/Rockwell hardnesses. Blasting for paint removal when you cannot change the base surface profile.
How Do You Choose the Right Abrasive for Your Application?
As a rule of thumb, you’ll want to choose a loose grain abrasive that is tougher than the substrate you are deburring or abrading but not so tough that you’ll damage the surface. The loose grain abrasive you choose will depend on:
- The item or part you’re blasting.
- The material you’re trying to remove.
- The substrate and material of the component.
- The project’s end goal — do you need a rougher finish for paint grip or a smooth, polished finish?
Your chosen abrasive could mean the difference between an irreparably damaged piece of sheet metal and a perfectly prepped surface that’s ready for a final coat of paint. In the best-case scenario, the incorrect abrasive could result in time-consuming, cost-eating deburring and finishing preparations that are not as effective as you would have hoped.
Fortunately, you don’t need to resort to trial and error to choose the right material and grit for your unique application. At Advanced Deburring and Finishing, our experts have a wealth of industry-specific knowledge to help you choose the correct loose grain abrasive and grit for the job.
Natural vs. Manufactured Abrasives
There are two forms of loose grain abrasives, natural and manufactured. Learn more about the applications of each to find out which is right for your situation.
Natural Loose Grain Abrasives
Some natural loose grain abrasives include:
- Garnet: Garnet is an aggressive abrasive. It’s great for cutting, deburring and abrading tough metals due to its angular edges. Garnet is also excellent if you need to prepare a surface for coating, as it leaves behind suitable grit. You can also reuse garnet multiple times due to its durability, reducing overhead costs.
- Aluminum oxide: Aluminum oxide is useful for many different applications, from light deburring to coat preparation — depending on the grit. It’s hardwearing, so you can use aluminum oxide abrasives several times before they lose effectiveness. But aluminum oxide produces heat when applied, so be cautious when using aluminum oxide on sheet metals like titanium and stainless steel.
- Walnut shells: Walnut shells are perfect for stripping despite being softer than garnet and aluminum. You can use walnut shells to strip or polish fiberglass, wood and other delicate substrates.
- Corn cobb: Corn cobb is also a safe abrasive for stripping or polishing soft substrates like wood and fiberglass.
Consider these manufactured abrasives for your applications:
- Silicon carbide: Depending on its grit, you can use silicon carbide loose grain abrasives to cut and remove stock quickly. You can also use silicon carbide for glass etching or metal sharpening. You can reuse the material, but eventually, the grit will wear down and become less effective.
- Plastics: Plastic abrasives come in a range of grits. They’re angular, so they’re perfect for stripping sheet metal on automotive or aerospace components. You can also use them on more delicate substrates like wood and fiberglass.
- Glass beads: Glass beads are perfect for peening or polishing sheet metals for a shiny, mirror-like finish. Round glass beads are not suitable for paint preparation as they don’t leave behind enough grit.
Get in Touch With Us for Loose Grain Abrasives
There’s even more variety than can be written down. Here is where all of our years, time and experience come into play. We know your specialized business and we’ll sell you the right system, including for loose grain abrasives. Consulting and sample part work is important in verifying processes and machinery prior to purchase.
Contact us today to learn more about which abrasive material is suitable for your application!