Nozzle selection depends heavily on the compressor you're thinking about purchasing, or the compressor you've got and are planning on using for your new blast cabinet.
For instance, a Husky 80 Gallon, 2-Stage, 5HP compressor delivers just over 15CFM at 90PSI, and they cost about $1,400. If that's the compressor you're running, then you're going to be limited to about 70PSI and a #2 nozzle with a suction delivery cabinet. That will work well, and definitely strip mill-scale, rust, paint, and old powder coat from parts...but it's going to do it a bit slower than if you had a larger compressor. To compensate for the lack of CFM, you can take advantage of a Pressure Pot/Vessel - they run extremely well from 30-50PSI, and because they are "push" media through the blast hose under pressure, they strip parts about 5-times faster than siphon guns, even when you regulate the pressure down to the 30-50PSI range. A 5HP compressor will be able to keep up with the demand without any problem, and you'll strip parts much quicker (about 5 times faster with the same #2 nozzle).
If you've got a 20HP screw compressor, you're going to push about 85CFM at 100PSI. Those run generally around $5,000. With this compressor to supply air, you can run a #4 nozzle on a siphon feed, and strip parts over 6 times faster than the #2 nozzle above (using siphon feed)...and the compressor will support that nozzle selection. If you decide to add a Pressure Pot to this kind of setup, you can bump the pressure to about 50PSI, and strip parts about 30 times faster than the #2 nozzle on the siphon setup above.
The Abrasive consumption in pounds per hour is in the chart because, unlike "open air" blasting where media isn't really reusable, all of that abrasive is recirculated in a cabinet, saving you tins of money! As the abrasive breaks down into dust particles, when the particle is small enough, our integrated Dust Collection removes them from the booth. Also, if you run a Pressure Pot, you really don't want to have the pressure above about 50PSI, because any pressure above that can easily obliterate the blast media, turning it to dust pretty much immediately.
The chart below shows the correlation between Pressure (PSI), and Nozzle Selection. Please refer to it for media consumption rates for different nozzle sizes, and if you need to talk to someone before you purchase a compressor, give us a call and we'll be happy to discuss your needs and offer sizing suggestions.
|CFM/PSI Abrasive Consumption Rates - Siphon Feed|
|Air/Abrasive Rates||50 PSI||60 PSI||70 PSI||80 PSI||90 PSI||100 PSI ||125 PSI|
|#2 - 1/8"|
|#3 - 3/16"|
|#4 - 1/4"|
|#5 - 5/16"|
|#6 - 3/8"|
|#7 - 7/16"|
|#8 - 1/2"|