Matching Compressor Capacity to Air-Assisted Spray Guns

The compressor needs to handle both the fluid flow and the air assist requirements. In this thread, pros explain the fine points. October 28, 2005

The Kremlin literature has me confused. They say the 10:14 uses only 1.1 cfm, yet they say the MVX uses 3-4 cfm. If you are using a MVX on a 10:14 this doesn't make any sense. I am asking this because I am wondering how big a compressor I would need to do on-site work. Does anyone have any suggestions?

Forum Responses
(Finishing Forum)
From contributor D:
I'm not familiar with the Kremlin. However, I believe it's because you have two air requirements - one for the pump, and one for atomization at the gun. Check with your rep. I'm not sure if you'd add the 3-4 cfm and 1.1 to get your total requirement, although it seems as though you would.

From contributor K:
To the original questioner: I understand your confusion and apologize for it. Contributor D is correct. The pump only uses 1.1 cfm to operate, but the gun uses 3 to 4 cfm for the atomization air. As a system, your total air consumption is around 5 cfm total. You can run this system off of most 5 hp compressors from your local hardware store or even an industrial grade pancake compressor with a 1.5 hp motor. Just so you know, a residential rated compressor does not produce as much air volume as an industrial compressor with the same hp rating.

From contributor B:
The 10:14 system uses nothing compared to the average HVLP setup. The difference is something like 6cfm (krem) vs. 17cfm-20+ (hvlp). And home depot compressors usually bog down with HVLP setups.

From the original questioner:
I have to say that I am still pretty confused. My 2 HP Emglow only puts out about 3.5 cfm if I am not mistaken. I don't know of any pancake that puts out more than about 2 so how can you run a 10:14 and MVX on that if combined they require 5 cfm? My 5 HP two stage Ingersoll only puts out 17 at 90psi. Upon further reading of the literature perhaps the discrepancy is where it says Inlet Air Pressure Range 20-87 psi. Now maybe my Emglow will do 5 at 50 psi. How often do you have to provide 87 psi to the 10:14? What is the usual range? It can't be over 50 if people are using pancake compressors.

From contributor R:
To the original questioner: Here's what I use at my finish room. I use a Kremlin 10:1 and my setup is: 10 to 30 psi air and 20 to 50 on the fluid, on mine the air is on the left and fluid is on the right. I have used a 20 gallon 4 hp compressor. Also when you do onsite work, your compressor will seem to constantly run and run.

So here's what I have done and it works perfect and if you can even afford a small electric airless I would suggest getting one. I only use the Kremlin in our shop because we have a large compressor and with an electric airless it’s just plug and play. I use a small Graco with a 4:10 ultra fine tip. You cant go wrong. You can cut your material just like using conventional or just spray it straight. Also - you alleviate having to pack a compressor with you .If I were you and even if you have to dig into your wallet again I would suggest going for the electric airless and use the Kremlin for smaller projects. I use the electric airless for catalyzed lacquers and catalyzed varnishes. You can shoot pigmented lacquers and varnishes too – just make sure to keep it clean.

From contributor R:
I have taken my Kremlin 10:14 on-site. The largest compressor I've used is a 3HP (and I doubt it's really 3HP) 20 gallon. It handles it quite well; it does not run all the time. I think it could be run off my 1.5 or 2hp Emglo (the little twin tank, 4 gallon pick it up by the handle) if the spraying was light and intermittent.

From contributor J:
To the original questioner: When looking at compressors look for deliverable cfm, this is the only number that counts. Then match that up to your needs.

From contributor B:
If you want to shoot fast with your AAA, just put a larger flow rate tip in it. I know that Sata makes tips with flow rates up to 53 oz/min and a 14" fan - normal flow rates are in the 10 to 15 oz/min range. With AAA you have the added benefit of excellent transfer efficiency and reduced overspray. Most will run off of a small 3 hp compressor as well.