Aluminum Oxide Blasting Grit: The Best Abrasive Media for Removing Paint?
Many manufacturers need help to remove paint from machinery. This step is important to prevent equipment corrosion and contamination of new products. However, there are many different methods for removing paint. Sandblasting with Aluminum Oxide is a common practice. Aluminum Oxide is a well-known abrasive blasting product that has been unchanged and available on the market for over 70 years.
There are a lot of variables that go into choosing the right abrasive media for removing paint. One of the most important factors is the type of surface or substrate that the paint is on — you need to be sure that the media you choose will not damage your surface or cause AIC (abrasive-induced corrosion) from particle embedment. Keep reading to discover the best abrasive media for your needs.
What Is Abrasive Blasting?
Abrasive blasting is a method in which small abrasive particles are blasted through a blasting nozzle under high pressure onto a surface using dry compressed air. They break down and remove an outside layer of paint or coating, which can be anything from rust, corrosion, or sacrificial zinc coating to chrome, paint, or a high solids epoxy-based material.
There are a few different types of abrasive blast media, including:
- Aluminum oxide
- Glass Beads
- Silica Sand
- Nickel Slag
Unfortunately, there can be some issues with these forms of blast abrasive. For example, silica sand contains high amounts of the regulated forms of respirable silica, which can be extremely harmful to the lungs — potentially causing lung inflammation or silicosis, which can be fatal.
Other abrasive media used in blasting can harm the underlying material. They may leave embedded particles on the surface, which accelerates the corrosion process and reduces the life expectancy of the protective coating. This creates a less desirable surface and an inadequate profile. Many alternatives also break upon initial impact, resulting in high dust levels that can be difficult to clean up from a workspace.
Aluminum oxide is one of the harder blast media available and is commonly used by many manufacturers to clean paint off their equipment. Aluminum Oxide is a sharp abrasive and tends to increase wear rates on blasting consumables like nozzles, blast hoses, fittings, and metering valves.
Glass beads are a gentle abrasive, unlike aluminum oxide. They create a smooth, peened surface finish and are often an excellent option for materials that can’t handle a deeper profile from coarser blasting abrasives. However, glass beads don’t leave much surface area in a profile, and this can lower the adhesion strength of some coating systems. Be sure to check with your coating system’s manufacturer before using this product.
Garnet is a mined mineral-based blasting abrasive. Because it has particle embedment and contains free iron, mild carbon steel will tend to flash rust over quickly in humid conditions, so the use of DH dehumidification is a must when blasting with garnet. It’s often used on steel, stainless steel, brick, and concrete surfaces, which can hold up to the intense abrading process. Although garnet can be used to remove paint from wood, it’s not the best choice as it may cause scarring.
Silica Sand was the original abrasive used for blasting steel. Hence the term ‘sandblasting.’ However, crystalline silica, sugar sand, beach sand, or any other crystalline silica-based sand is dangerous. Blasting with silica sand can result in silicosis, severe illness, and even be fatal. It is a naturally abundant and inexpensive material, but now that the health hazards are understood, it should not be used as a blasting abrasive.
Nickel slag is a common abrasive material used for blast cleaning. It is created as a byproduct from the slag produced during nickel smelting. Nickel slag has an average Mohs hardness of 6.5, and its particles tend to break apart quickly while blasting. Because of this tendency for nickel slag particles to rapidly pulverize, the abrasive is really dusty during blasting. Watch the video below for a demonstration of the dusting levels present when blasting with nickel slag compared to a superoxalloy.
Safety Issues With Abrasive Blasting
Abrasive blasting with blast abrasives can be extremely dangerous. Dust can emanate from the work area and be inhaled by workers. This fine dust consists of used abrasive and pulverized paint, and it’s often hazardous to breathe.
All employees who work with blasting equipment need OSHA-approved PPE to protect their lungs and eyes from the dust. It’s also essential that employers have a plan in place to protect the rest of the work environment from being infiltrated with dust from blasting to prevent accidental exposure.
What’s the Best Abrasive for Removing Paint?
Many companies choose to use traditional abrasives for their projects. However, there are new superoxalloy abrasives that offer several advantages over traditional blast media. These abrasives are made of an alloy of oxide minerals engineered for optimal blasting performance.
Superoxalloy abrasives leave a substrate virtually free of embedded particles so the surface is ready for another coat of paint. Their non-crystalline particles resist breakage and can be reused many times — making better use of your equipment and budget.
In addition, superoxalloy abrasives are safer because they are biosoluble. Because the composition of mineral wool and superoxalloy abrasive particles are identical, blasters can feel confident that the safety of the material has been extensively studied and understood for decades. No other abrasive material has been as extensively tested, studied, and verified for safety. The World Health Organization (WHO) International Agency for Research on Cancer (IARC) Agency reviewed decades of animal and human studies of long-term exposure to high air concentrations of mineral wool dust. The 2002 IARC Monograph (Volume 81) determined that mineral wool dust is bio-soluble in the lungs and is not classifiable as carcinogenic in humans (Group 3). This IARC categorization removed the material from lists of possible carcinogens everywhere in the world. They also have ultra-low dust. When you use this type of abrasive, the air quality in your facility poses less of a danger to employees and the environment.
Choose Superoxalloy Abrasive From 10X Engineered Materials
At 10X Engineered Materials, we’ve designed two types of superoxalloy abrasives — KinetiX and EpiX — to better suit your needs. EpiX abrasive is best for precision applications such as powder coating and medical applications.
In one of our customer testimonials, a painting contractor found that the KinetiX 20/40 superoxalloy abrasive immediately cut through about 250 mil of coatings and reported that no other abrasive had been able to remove that many layers.
Contact us today through our online form or call us at 260-253-2278 to learn more!