Basic Air Brush Questions

[iambrb]

Ok so I am having to re-learn how to use my air brush (Paasche VL), and I have some issues, please help!

My FIL gave me a 100PSI Oiless Compressor with a 'pancake' air resivior
(This is it: http://www.walmart.com/ip/Factory-Reconditioned-Porter-Cable-C2002R-0.8-HP-6-Gallon-Oil-Free-Pancake-Air-Compressor/37470725).
and I have my Air Brush hooked up to it. However, what I am finding as I play with food coloring and paper towels is that:

A- really hard to do anything under about 20-30PSI, and even then it come out with considerable force. Does not really want to refill the resivoir @ less than 25 psi or so. Don't I need less pressure for model paint?

B - when I am able to spray, I can get an OK pattern for say general coverage (like a rattle-can), but how do I go to a fine pattern or point, like for more intricate camo?

Please help!

 

[ausf]

You need to put a regulator between the compressor and the AB. That way you can dial it down as low as you want and it won't effect the compressor's guidelines for tank refill/etc.

Generally, you'll want to AB in the 12-35 PSI range depending of paint/pattern.

In terms of the VL, I'm not familiar with that particular one, but a quick search shows you should be able to get a relatively fine pattern. Check the needle/tip size, but also make sure the needle is set nicely in the nozzle. You should be able to spray air without paint, then slowly add paint to the mix.

Distance to the subject also matters in terms of pattern. To get some fine lines with my Iwata, I need to remove the little crown end cap, which gives you an idea how close it can get to the surface.

 

[Adam]

There are a number of things that are going to affect you here. I used a VL for many years and you should have no problem going down to a low PSI with it. I see from the link you posted that your compressor has a regulator. Are you saying that when you turn it down below 25 psi that air won't come out? Something is then wrong. First off try this. Get the compressor filled up with air. It should have an auto shutoff of about 125 psi or so. Then turn the regulator all the way down to zero and then slowly bump it back up to the pressure you want.("Normal" airbrushing pressure is about 10-20 PSI) That should get you where you need to be. If that still doesn't help you probably have either a blockage in your line or in your brush. Is your brush clean?

Secondly if your paint isn't thinned enough it will have a hard time coming out of the airbrush. Normally you want about a 50/50 mix of paint and thinner but that is not at all a hard and fast rule. You really need to play with it til you find what works for you and your paint types.

Thirdly for a fine pattern you want to go with a more thinned paint, lower air pressure, and a fine needle and tip. Do you have different sized needles and tips? I know my VL came with two needles and tips. I can't remember the sizes but one was for fine work and one for more general coverage. In reality though ever with a larger tip on an airbrush you should still be able to get a pretty fine line. The key is your paint mixture, air pressure and a real steady hand. You gotta get in real close and go slow.

Last of all, this is just my advice and others will have different. There are as many different opinions and techniques as there are airbrush users.