Glass Beads vs. Crushed Glass - Finishing Systems

Glass beads and crushed glass are both effective abrasives to produce a desired finish on a part. Glass beads are commonly used in a blast cabinet or reclaimable type of blast operation. They impart a consistently bright matte finish on aluminum and steel substrates. Crushed glass is most desirable for removing heavy coatings, paint layers or rust to expose a clean and bare surface. Although they’re both manufactured from glass, the final finishes produced can vary.

Tenroads Product Page

If you’re trying to decide what abrasive is best for the job at hand, comparing glass beads and crushed glass is a crucial way to determine if one of these options is right for you.

Contact Us

When to Use Glass Beads

Glass beads are best suited for finishing metals. They can be used for frosting and etching glass, among other typical applications:

• Cleaning (perfect for surface preparation without changing tolerances or imparting ferrous contaminants)
• Finishing (varying sizes create a wide range of unique surface finishes and blending of machining marks)
• Peening (reduces the tensile stress in metal components, increasing fatigue limits)
• Deburring (successful removal of burrs without any part damage resulting in a smooth peened surface)

A benefit to using glass beads is that they are environmentally friendly and contain no free silica, a common concern in metal finishing operations. Generally found in traditional sandblasting media, free silica can release harmful chemicals during the abrasion process. While companies can still choose silica sand, more regulations are required due to workers’ increased risk of severe respiratory disease.

The size of the bead, your specific workpiece shape, the distance of the blast nozzle, air pressure and the type of blasting system all play an essential role in the final finish and your abrasive consumption. You can recycle glass beads multiple times if used appropriately. When selecting glass bead blasting equipment, consider a sandblast cabinet to help recover this blasting media for effective reuse.

Glass beads are an ideal abrasive, helping you save both time and money. When you can spend less time on one cycle, you can get through more cycles faster if you have a large number of items that need blasting. The available range of sizes ensures you produce the desirable finish on your parts. Experienced glass bead blasting media suppliers can help you choose between coarser glass beads and finer ones.

Whichever type of glass beads you choose, all will give a bright, smooth and more satin-like finish.

When to Use Crushed Glass

Crushed glass, due to its irregular crushed shape, produces a greater etch on your workpiece, making it practical for surface preparations where subsequent coatings may be applied. Our crushed glass is superior in various applications for its performance, health and environmental benefits compared to other abrasives.

• 100% recycled glass can be reused many times and is favorable for safe disposal.
• It’s environmentally friendly, with non-toxic chemical properties reducing pollution risks.
• It’s non-reactive and chemically inert, reducing rust back and making it safe to use around water.
• It contains less than 1% free silica compared to silica sand, which contains up to 99% free silica.
• Our SDS does not list beryllium, a heavy or toxic metal commonly found in slag and other abrasives.
• The natural, white post-blast finish creates an attractive final finishing step.
• It significantly reduces embedment issues which occur up to five times more in slag blast media.
• It’s translucent, meaning visibility and productivity are increased substantially.
• It’s less dense than other abrasives, resulting in less material usage and reduced media costs.
• Depending on the select plant, it may be both QPL approved or CARB approved.
• It’s SSPC AB-1 Class A, MIL-A-B(SH) approved based on toxicological safety evaluations.

While both are commonly used to finish metal surfaces, abrasive blasting and sandblasting are distinct processes advantageous for different circumstances and projects. Using glass beads for sandblasting is less conventional. However, you can use crushed glass blasting media with a standard sandblast pot.

Gradations and Profile Guide

Crushed glass is available in a range of sizes, each resulting in various Mil finishes.

MEDIUM 1.0 – 2.5 MILS : Typical 2.3 MIL (SSPC-AB1 Grade 2)

If you are looking for more details, kindly visit Blasting Glass Beads.

Cleans and polishes surfaces for a smooth, white finish. Ideal for automotive, dustless blasting and as a soda blast alternative.

MEDIUM – COARSE 2.5 – 3.5 MILS : Typical 3.1 MIL (SSPC-AB1 Grade 3)

Suitable for bridges, tanks, steel construction, and precast concrete.

COARSE 3.5 – 4.5 MILS : Typical 3.8 MIL (SSPC-AB1 Grade 4)

Ideal for bridges, tanks and steel construction and precast concrete, and where a deeper profile is desired.

Choose Glass Abrasives From Finishing Systems

Finishing Systems is known as a top blasting media supplier for glass beads and crushed glass. We provide finishing solutions and products to companies large and small for a wide range of uses. Whether you need to strip paint or remove rust, our abrasive blasting equipment can deliver the results you desire without damaging the material’s surface.

To learn more about glass beads, crushed glass or other abrasives, please contact us today!

Updated January : Almost all of our blast cabinets are able to use glass bead abrasive media. Most operators and manufacturers know when to use glass beads and why. We’re sharing some tips that we’ve picked up over the last 50+ years in this industry remember Media Blast  manufactures more than 180 machine models.

5 Reasons to Use Glass Beads in Blast Cabinets

1. Recycle Rate. The harder the blasting abrasive the more times you get to use the abrasive, normally. This is known as the Recycle Rate and normally you can find the different harnesses on the Mohs Scale for Mineral Hardness. You can easily access a list but understand we are normally talking about minerals and this scale measures hardness from the softest (Talc) to the hardest (Diamonds).
2. The round shape of glass beads makes them stronger than glass typically ranks on Mohs Scale of hardness. Let us explain: Glass beads normally bounce off steel parts using 80 psi siphon delivery and 40 psi direct pressure delivery. Other abrasives with a similar ranking on Mohs Scale shatter the first time they hit a steel part at the same speed. This turns the machine area into a huge mess while overloading the dust collector.

ProTip: Garnet, slag abrasive, and glass beads all rate about 6.0 on the Mohs Scale. Garnet and slag are not recommended for blasting cabinets; yet glass beads are one of the most used recycle abrasives. Why? The secret is in the shape, ROUND!

3. Abrasive glass beads are fairly cheap considering they can often be recycled twenty to thirty times when used properly. Some operators might think it’s a good idea to turn up the air pressure to increase abrasive blasting pressure and cut processing time. Unfortunately, increasing abrasive blasting pressure can cause the glass beads to break apart. This reduces the recycle rate and increases the cost of the abrasive but more importantly it can overload a dust collector.

ProTip: If you are buying an inexpensive abrasive like slags that recycle very few times, it’s good to reference that glass beads recycle 20 to 30 times. So you may actually be paying more for slags which create a huge mess when they quickly plug up any dust collector.

4. Cabinet Visibility. Blasting glass beads, unlike dark, cutting abrasive, impact and spin against parts. They remove nothing from the surface and make a small, moon crater with the displaced material around the hole. This is called a physical part surface change and is technically making the part larger if you only measure the peaks of the surface. Chemically changed surfaces occur when the part surface is changed into something else. The sealed surface collects more light, similar to a mirror telescope, and makes the part brighter in color. This improves visibility inside the cabinet. Glass Beads are the same product used in the painted lines on roadways. Glass beads cause the lines to glow when your headlights hit them.
5. Peening and Part Strengthening. Peening makes a part stronger by eliminating surface scratches. When surfaces have flaws created by cutting threads, machine marks or something else, the integrity of the part surface is compromised. Shot Peening parts, normally done using round steel shot and direct pressure delivery, removes the deepest irregularities from the part surface. Softer parts like aluminum can be strengthened using glass beads and shot peening. Peening degree (intensity) has different scales based on how strong you want the part to become.

ProTip: Larger beads do not withstand the same pressure as smaller beads. Normally you need to reduce the pressure about 15% when blasting a stainless steel part, and even more when blasting super metals. The abrasive delivery method should also be accounted for because siphon and direct pressure have very different maximum impact velocities.

To Sum Up Using Glass Bead Abrasive Media

Blasting glass beads are a great choice for most abrasive blast cabinets because they recycle when used appropriately, maintain the integrity of most parts they contact, and improve visibility. Many of our abrasive blast cabinets are designed to use glass beads, check out our extensive line of machine models today.

For more information, please visit 80 Grit Glass Bead.