Abrasive Blasting with ARMEX™ Soda
BEST OF BOTH WORLDS: COMBINING THE POWER OF ARMEX™ WITH VAPOR ABRASIVE BLASTING
Sodium bicarbonate blasting, also known as baking soda blasting, has been used for abrasive blasting for only the past 30 years. During the 1984-1986 restoration of the Statue of Liberty, hard abrasives were used to dry blast the interior of the statue.
After this method was found to damage the underlying copper substrate, restorers turned to a commercial grade of ARM & HAMMER™ sodium bicarbonate – baking soda – to remove the final layers of paint without damaging the copper underneath. When the process worked, ARM & HAMMER™ donated all of the soda for the project, and the first soda blasting media ARMEX™ was born.
What Separates Baking Soda From Other Media?
- Non-destructive cleaning: Baking soda is unique in blasting because it offers non-destructive cleaning and substrate preservation. When blasting with hard abrasives, the particles impact the surface and not only remove the contamination but also remove substrate materials. Hard abrasive blasting can also wear through substrate material if the blast operator dwells on one area for too long. Using baking soda as a blasting media won’t damage substrates or place profiles into the substrate surface.
- Easy to clean up: Baking soda is soluble, meaning it will dissolve in liquids like water and oil, removing the need to worry about blasting particles being left behind on surfaces after a fresh water rinse. Consider dry blasting engine parts using sand or glass – any particles remaining in the engine would need to be cleaned out. Even a tiny particle left behind can cause problems in a delicate system.
- Paint-ready: Blasting with baking soda is a simple way to make surfaces paint-ready. Soda will re-expose the previous profile and remove the surface contaminants, making it immediately paintable. Plus, the sodium in baking soda offers anti-corrosion properties, helping prevent rust from re-appearing on soda blasted surfaces.
- Environmentally friendly: Baking soda itself is non-hazardous, and can be thrown away in the regular trash or even flushed down the drain. Typically, the only hazard you may encounter is the contamination you’re removing. In blasting, the amount of soda used helps reduce the hazard of the contamination – because the ratio of contamination to soda is so low, both can usually be tossed in the trash. Choosing soda blasting over other methods also alleviates the need for solvents and chemical cleaners, which expel volatile organic compounds (VOCs) into the environment.
What Makes ARMEX™ Different?
- Formulation variety: ARMEX™ offers 11 different formulations, each one specific to a certain type of cleaning task. Blasting paint off a brick wall might need a different media than blasting carbon fiber or electronic circuit boards, and ARMEX™ is prepared with options. Customers can send samples to be cleaned to the ARMEX™ technical center where technicians will test them to understand the project and help them pick the best formulation and cleaning process.
- Flow aid: ARMEX™ products have been formulated to include flow aids. Baking soda is a natural desiccant and easily absorbs water. If the compressed air is not being filtered for oil and moisture during dry blasting, the soda can clump and clog the blasting equipment. ARMEX™ flow aids help prevent clogging of equipment.
- Moisture control: Taking it one step further, certain products have additional moisture control capabilities, which help prevent water absorption and preserve product during storage in high moisture and humid environments.
- Grit size: Generally, the heavier the contamination, the larger grit size you will need to remove it. ARMEX™ works with customers to help them select the proper formulation, grit size and moisture control options needed to make their project a success.
- USDA A1 Approved: ARMEX™ is the only USDA A1 approved baking soda media supplier on the market. This certification allows ARMEX™ to be used in and around areas that are in contact with food, such as food processing plants.
Using ARMEX™ in Vapor Abrasive Blasting
So far, soda blasting sounds like an incredibly effective way to remove contamination without damaging surfaces. But what’s the downside?
As with all dry blasting techniques, the downside is dust. Any dry blasting media creates dust that floats everywhere and gets into everything. To prevent the dust from coating the project, containment must be used. In some cases, the project being blasted can fit easily into containment. In other cases, such as large, awkwardly shaped projects or projects that can’t be easily moved (a parking garage for example), containment can be a time consuming and expensive step.
No blasting process can truly be dustless, but with vapor abrasive blasting, the dust is reduced dramatically compared to dry blasting. Less dust makes for a much more user friendly and easier to clean up process. The Graco EcoQuip 2 Vapor Abrasive® Blast Systems feature a pump that pressurizes a pot of water and media. As water is metered into the pot, the media flows into the blast circuit and through the hose and nozzle during blasting. The precise control of the wetted media results in significant dust reduction without sacrificing productivity. Additionally, only approximately ½ to 1 quart (0.47-0.95 L) of water exits the nozzle per minute.
Before and After: ARMEX soda blasting
for fire damaged wood
To ensure soda blasting works with the water used in vapor abrasive equipment, look for the right ARMEX™ formulation. By choosing a formulation with the correct amount of moisture and flow control, such as the Maintenance or Maintenance XL product, the baking soda does not dissolve immediately in the water. Too much moisture control won’t work, though, as the soda and water need to combine to make the vapor abrasive blasting work.
The combined power of soda and vapor abrasive blasting makes it an excellent choice for many applications where non-destructive cleaning with as little dust as possible is important, such as historical preservation, graffiti removal or fire and mold restoration.
To learn more about ARMEX™ products for your next blasting project, visit www.armex.com.
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