CFM and compressors

[ManU07]

Hi gurus,

I have never used a spray gun before but recently purchased a STAR HVLP gun and being a complete noob i hooked it up to my dodgy Bun**ngs compressor and lo and behold its not atomising and generally is absolute rubbish. I have since learnt that my compressor is not up to the job both in volume and flow rate. My question is what can a weekend hacker like myself get away with? I cant afford the big heavy duty compressors so what is everyone's experience with their compressors and what have you found will do a passable job on HVLP? I have read on some sites that the compressor may not need to meet the full cfm requirement as specified on the gun but don't want to waste $$ on a compressor that wont do the job.

FYI, the spec for the gun suggest up to 15cfm but the best i can find in my price range is about 10cfm.

TIA for any advice.

[riverbuilder]

I have a couple of these ones SENCO 2.0HP 50L Oil Free Direct Drive Air Compressor AC24050 | Total Tools

ive done heaps of spraying with them and they’ve been fine. Have you thinned the product that you’re spraying? This is important for atomisation. The main thing with the smaller compressor is to drain the tank regularly (every day) and put a secondary water trap like this in the line before the hose to the gun IRONAIR Air Compressor 3/4inch Air Filter | Total Tools

[BobL]

Most air appliance manufacturers understate air requirements and compressor manufacturers do the opposite. My limited exposure to HVLP guns has been underwhelming and found it easier and better using a small high pressure gun.

[ManU07]

thanks riverbuilder,

i have thinned down the paint (this is just for painting household trim at the moment but would like to transition to more refined finishing over time). Appreciate the info, there is no doubt that the compressor i have is not up to the task so will try hiring something with similar specs to what you linked to and see how that goes, if it goes well i'll go ahead and purchase something in that range.

[blouis79]

My Anest Iwata LPH-300 is supposed to require 200-240L/min according to the manual depending on the nozzle size in use.

In practice, I have had no problems with air supply spraying cabinetwork with Sikkens water or oil based using the cheap SIP 2.5HP direct drive compressor, which should only output 180L/min FAD.

Stop start spraying uses less air and the air tank will deliver more than the compressor.

It may be that the Anest Iwata design is especially efficient at atomising, which the manufacturer's information suggests (patented split nozzle design). Spraying fast and close may also help (suggested by an Anest Iwata spray guru in USA).

Other apparently important things:
- gun mounted pressure regulator (not jut a flow control) since atomisation is determined by pressure at the gun
- viscosity test cup
- paint thickness comb gauge
- disposable paint cup system