HVLP & CFM's Understanding

[Carroll Courtney]

How do you go about selecting a hvlp spray gun to work w/your compressor?My problem is I just don't understand the setup.I have one compressor that will produce 18cfm's at 40psi,its a 80gal 5hp.Then I have the small dewalt that everyone see's at the home centers.It produces 4 cfm's at 40psi.I would like to use this gravity feeded gun on either compressor,if that is possible.Looking at the gravity feed guns,the info is confusing for me.Avg.air consumpt is 9.6cfm's(7.8cfm@40psi)10psi operating pressure.I have a filter and a regulator mounted on the wall then w/the quick disconnects and the air hose.I have been told by others that I will need to go to a bigger hose from 1/4 to 3/8 because of the restictions.I have order this gravity feeded gun and it also comes w/a small regulator mounted on the gun.The gun comes w/a 1.5mm tip and a 1.7mm tip.These were recommented,for thinner and alittle thicker paint or clear finish.I guess in a nut shell,how would you go about setting this up.What to set the main air regulator at and then what to set the regulator at that is mounted on the gun.Then how does this get to 10psi to be called HVLP,does it do this inside of the gun,or is that what I set the gun mounted regulator psi at?Are is there any web sites that could put this into laymans terms to where I could understand this?Confuse,and in need of help Thanks Carroll

[frank shic]

carrol, since you have a good sized compressor, you can easily get one of those conversion guns grom gleempaint and plug it into your air compressor - it'll work fine with your current specs. use water-based coatings and you shouldn't have to do much thinning either. good luck.

[Bill Neely]

Carrol, when you get the gun it should tell you where to set your line pressure (from your compressor). Then you adjust the small regulator on the gun by pulling the trigger and adjusting the pressure drop. For example mine wants about 35lbs from the compressor and 14lbs at the gauge on the small regulator when I hold the trigger down. 1/4" hose is generally a little too small to run an HVLP gun, a 3/8" hose with high volume fittings is best.

It's high volume, low pressure so the big compressor is perfect.

I think you'll like the gravity flow gun, I love mine. Devilbiss makes ziplock bags that come with adaptors to fit many different guns. You can then spray upside down and cleanup is very easy.

Good luck

[nic obie]

Carroll,

Check your messages.

BTW a 3/8" hose is a good idea but your 1/4" one should work if you keep it short and the pressure on the wall around 80 psi.