Abrasive Blasting 101
Question from the MBA Contact Us page: “What is the best blasting cabinet for a Powder Coating Shop? As a shop owner, I need a blast cabinet capable of removing old coatings quickly.”
Answer: There are many different types of powder materials ranging from really tough thick powder coating to some about the same as paints. The best blasting cabinet for these projects is dependent on what type of powder and paint was used, and some of the really hard powder requires burning off then blasting! Epoxy paints and hard powder coatings typically turn soft with most small 5 hp air compressors using either siphon or direct pressure abrasive delivery.
ProTip: Many Powder Coating Shops use garnet in blast rooms. Garnet is seldom used in blasting cabinets that recycle and clean abrasives because it’s too soft and has a low pressure blasting impact velocity. This means garnet recycles only a few times and can quickly overload and plug almost any dust collector.
A direct pressure, industrial-quality, plastic blasting Cabinet like the Media Blast Hailstorm is very commonly used for quickly stripping powder coating. Keep in mind the compressed air used is what delivers the abrasive that cleans the part. So, the air volume your cabinet uses is very important. Low cfm usage, even at 100 psi blasting pressure, creates low frictional heat resulting in slow cleaning that’s good for slow texture only.
Another component of the best cabinet for powder removal is that different mesh sizes are used to prepare the part surface for special finishing such a hook pattern, a gloss, semi- gloss and matt finish. Buying the right machine to create your desired finish isn’t as simple as going to the Internet, typing in “sandblast cabinet” and buying a cabinet based on looks alone. It’s important to research the type of abrasive used and understand the features of the cabinet based on your specific projects. Any of Media Blast’s many models are capable of achieving special finish effects when the part is blasted before coating.
ProTip: Plastic abrasive does not texture the part surface so cleaning with plastic is not its application but an abrasive used to remove coatings.
Many light duty blasting cabinets are described as “Heavy Duty” or “Industrial” but they are not! Industrial blasting cabinets include adjustable separator reclaimers and very large dust collectors with self-cleaning features to clean during blasting. An Industrial cabinet can easily deliver one million pounds of abrasive out the nozzle per year using a quality abrasive, if it has a separator reclaimer and large dust storage filter area. Buying a machine operating on low cfm gun sizes means lower frictional heat and increased part processing time. Slow cleaning speeds demand hours and hours of operation that the dust collector can’t support and you end up with a real mess and increased labor costs.
Industrial Siphon Cabinets like the Media Blast N-200 and N-200 Cyclone can be faster and better choices than direct pressure for creating a surface hook pattern on new parts that you need for gloss to matt finish.
Most powder coating facilities have direct pressure and siphon cabinets as well as blast room supported by a 250 to 500 cfm compressor to process parts as quickly as possible. Ideally, we’d recommend all three to shop owners with enough capital and square footage in their shop.
For smaller powder coating shops one blasting cabinet may be all that is purchased so the one that’s best depends on the volume of air you have and the type of work being done with the blaster. Here are a couple of quick tips to remember:
Media Blast & Abrasive has been manufacturing sandblasting cabinets since the 1970s. We make more than 50 models totaling 180 individual cabinets with some models available in as many as 13 different sizes. In addition to a comprehensive list of included features, we offer more than 80 optional features for increased productivity, durability, and operator safety. If you’re not sure what cabinet is the right fit for your needs, give us a call or visit our Buying Guide.