Abrasive Blasting 101
Buying an air compressor for a blasting cabinet can seem like a daunting task, we know. Media Blast manufactures the largest line of Wet Blasters, Dry Siphon, Gravity Feed and Direct Pressure models with categories for Light Duty, Automotive, Sandcarving and Industrial abrasive blasting. Depending on what model you purchase and where you’ll be operating it, there are a few components that will affect your air compressor needs.
Pro Tip: We always recommend taking your foot off the pedal any time you’re moving the part to simply save air volume. Know the air volume required is measured in “volume per minute” or cubic feet per minute (cfm) and if you simply remove the blast for 5 seconds every minute you just saved 8% of the cfm usage per minute. That’s like only needing 15 cfm to operate any machine requiring 16.6 cfm.
Before we dive in there are four critical things to know before you buy an air compressor for abrasive blasting. If you’re not sure what they are, take a quick minute and read this to refresh your memory. Check out these five great tips if you’re in the market for an air compressor. Also, if you know you’re planning to buy a piston air compressor, check out these six facts specifically related to piston air compressors to help you choose the right compressor for your needs.
Pro Tip: If you plan to operate close to the max air compressor pump volume (cfm) know the tank is also a chiller. All compressed air exits the pump as hot air and goes into the cold tank for storage. Just like your air conditioner at home or in your car creates moisture so will hot air entering a cold storage tank. After prolonged use the compressor tank will warm, accumulate water and the air will again leave the tank warm and full of moisture. Next the compressed air enters the cold steel blasting cabinet where it can again create moisture. Wet air is a bad thing in dry blast cabinets, but you can install many different types of air dryers or coolers to remove the moisture. We like an Ambient Dryer that connect to the air inlet of the machine and removes moisture from the air being used by the abrasive blaster and not the entire air compressor.
Now it’s time to put all this into buying a compressor for your application and if you plan on using the machine more, blasting for long time periods or using direct pressure delivery buy at least 1-1/2 to 2 times the air needed to operate the unit. As a direct pressure nozzle wears out it needs more air volume to hold the blasting pressure, so unless you want to keep buying new nozzles, buy more compressed air if you can.
Real World Example:
Let’s say we’re buying a small home shop siphon blaster with a standard nozzle size and recommended 16 cfm usage at 80 psi blasting pressure. We also know we’ll be using glass beads and want to make sure we extend their life-cycle as long as possible, so we refer to Media Blast’s compressed air chart to check cfm usage vs. nozzle size and blasting pressure. Next you find out the maximum impact velocity of the glass beads to know if you need higher blasting pressure or lower blasting pressure.
The power panel that will operate the air compressor is single-phase power limiting the compressor motor size but more important the amount of air you will get from a single-phase power compressor model.
Choosing the right air compressor for a blasting cabinet can seem overwhelming. If after reading this blog you still have questions, give us a call. We’ll help you select the right air compressor for your machine and application.