Abrasive Blasting 101
We’ve written a number of blog posts discussing compressed air, but now we’re going to address some of the most frequently asked questions we get about the subject. For more information about buying an air compressor check out Air Compressor 101: Everything You Need to Know.
Q: What voltage do I use for a Home Shop or Small Shop air compressor?
A: 220 volt single phase is the answer. Most compressors designed for home blasting cabinets are built to run on a single phase 220V electrical power. As you move from smaller less expensive blasting cabinet to larger blasting cabinets you must normally need 3-phase electrical power to operate the air compressor. If you see a blasting cabinet indicating 6 cfm air usage we suggest passing on the purchase. There’s nothing worsethan a disappointing tool and 6 cfm will be very disappointing! Home power is rarely 3-phase power supply.
Q: What happens if there is water in my air compressor?
A: First, there is always water in all air compressor tanks. Hot air hits the cold tank and the hot air produces water as it cools. The same thing happens when you leave a salt shake out in the rain, it stops flowing. Dry abrasive does not flow when it gets wet! Wet air must be cooled to remove the water; hot air will pass through the air filter water trap as a vapor then cool inside the cabinet producing water. It also plugs the dry machine dust collector filter very quickly.
Q: Can you store more air at higher air pressures?
A: Yes, a higher compressor storage tank pressure will increase the volume stored inside the tank. At 175 PSI, an 80-gallon tank will store more cubic feet of air than the same 80-gallon tank at 100 PSI and all guns are using cubic feet per minute. This is why it’s important to do your homework and make sure you’re comparing apples to apples when you’re choosing between similar looking air compressors.
Q: I see the same looking compressors, same tank size, selling for lots more money, why?
A: When you are talking smaller air compressors operating on 220-volt single-phase power normally the first reason is the compressors stages or pumps itself. Two stage air compressors use a second stage to take the air from the first stage and push the tank pressure even higher. Remember high pressure mean more storage inside the tank.
Q: What is the difference between all cast iron and cast iron sleeves?
A: Many cars now have aluminum blocks but all have cast iron piston sleeves. Cast iron means the compressors will take more heat and more abuse, which is why trucks have cast iron blocks. Most 100% duty cycle compressors are all cast iron for durability. The first Vega cars by Chevrolet were aluminum blocks with no cast iron sleeves, the motors were worn out at 40 thousand miles, mostly all of them!
Q: What is the best way to cool air?
A: Many answers to this question but the most cost efficient is an ambient dryer. Instead of cooling all the air you cool at the machine, this allows a smaller dryer. Industrial will do just the opposite, rather than buying lots of ambient dryers they use one big dryer and cool all the air at source?
Pro Tip: The number one mistake people make when choosing an air compressor is going with too small a model because it’s less expensive. Smaller compressors have lower cfm, faster running pumps and smaller tanks. Smaller 4 cylinder engines in cars work harder to get you down the road, they cost less to make and they do not last longer than larger slower running 6, 8 and 10 cylinder engines. Always buy double what you need and let the compressor rest, it will cool and last longer.