compressor pressure question

I was reading a recent article where the (expert) shot everything at the same pressure and changed only his mixing ratio, his theory was 1 less variable to deal with. Kinda made sense, His work was beautiful by the way and I've played around a little myself and yes the amount of thinner made a difference. It was the Oct 2014 issue and the gentlemen was Simon Harrison. I personally don't know much yet as I just started but I found this article very helpful.

There is no one pressure that works for every purpose.  The thinner the paint the lower the pressure, but it also depends on how fast the paint dries.  It is something you learn with practice.  Lots of practice, sometimes, unfortunately.

You didn't mention the type of AB you're using - a siphon feed will require higher pressure than a gravity feed, but not a lot. How accurate is your pressure gauge? Or maybe a better question is how big a gauge is it? Most shop type compressors are used in the higher pressure settings so the gauges display these well and don't pay attention to the 0-20 range.

An easy way to fix this is to find a larger gauge that displays the lower range well. Another is to put a low pressure gauge and regulator between the source and the AB hose so you're reading how much pressure you have "at the gun". The latter is what I use so that I can accurately repeat the settings.

Hope this helps!

Mike

 

I have a rather large compressor i use for carpentry work ( and airbrushing ) so I bought a digital pressure guage for cheap at Harbor Freight and installed it on the AB hose. It works very well and is accurate within 2 PSI. I send 40 PSI to the AB and can easily dial it down to 6PSI or whatever I need .

I have a gravity feed Badger Patriot and when in close , it sprays well with  fine lines at 6PSI. My siphon feed Badger VL ,on the other hand ,needs lots more pressure to operate so pressure also has a lot to do with the kind of AB you have as well.

I wonder how Simon Harrison gets fine lines AND wide spray patterns with the same psi.

Don't forget about the Painting and Airbrushing forum.  Some good threads on topics like this.

I haven't had much luck in the 10-15 psi range and I too read about folks using and recommending it often.

Often wonder if they are using solvent based paints. Except for primers, I spray mostly acrylics.

Just my

NO matter how much I've tried to find a standard pressure, I'll always end up fiddling around a little at the start of every session.

I get best results with lightly thinned paint, at about 30 psi.

Thanks to all that responded. The general understanding I get from all that responded is pretty much what I was forced to conclude myself. What comes out of the tip should guide you as to any adjustments you need to make. I have to add that life has certainly changed with acylics. They're excellent and certainly better for our lungs then enamals but they have unique characteristics that need to be accounted for. With my set up and, I must add, a cheap two stage, the pressures that work best for me are somewhat higher then are often times quoted. Most anything I do requires me to be in the 20 to 35 psi range. After hearing from others I can accept the difference and as everyone will agree the results are what matters.

Thanks to all.

rbtvgo

You do need higher pressure if you consider an airbrush as a substitute for a spray gun.  However, I think you get a better finish if you think of the airbrush as a brush that puts down a brushmark-less finish.  Cover small areas, which is best done with lower pressure and closer distance between airbrush and model finish.

I generally use 15 psi, go up to 20 occasionally for really flat flats.

Another factor may be the airbrush and the manufacturers recomendations for pressures depending upon the type of material being sprayed and the tip size being used. As mentioned above practice and use whatever gives you the best results.