What is the recommended PSI for airbrushing?

Model Railroader General Discussion (Model Railroader)
1

I have a Paasche H airbrush. What is the recommended PSI for airbrushing? Are there any rules for this?

2

I learned to always test them before I decide on PSI. Different paints need different PSI. You dont want it where it just splatters on and you dont want it where it cakes it on either. I stay about 25 to 30 psi since I can controll how much aitr comes out of my airbrush.

3

Doesn’t the brush manual recommend a pressure. I have an old Craftsman that recommends 10-18psi.
I think the thinning has more to do with it than anything else.
Peter

4

A lot depends on the paint. I normally run around 25-30 psi but I also have a dual action airbrush. Best sugestion is to set it at 25 psi and test what ever your spraying on a piece of paper to ensure you have a correct pattern and coverage. Also I always thin my paint to the consistancy of milk before painting.

Curt

5

It also depends which needle is being used. The higher the volume of paint the higher the pressure is needed to move it. The thinner the paint the less pressure is needed. I prefer thin paint and usually use 10-12 psi. Too low a pressure and the paint could dry in the air giving a matte finish - acrylics are especially difficult in this regard. Too high a pressure and the paint hits the surface and splatters which can also result in a matte finish or a smeared look.

Choose a needle. Choose a paint. Then practice with different thinnings and different pressures until the result is what is desired. Then record that combination for that paint so it doesn’t have to be “discovered” again.

6

I use right at 28 psi for my Aztek.

7

Thanks guys. Good answers as always. [:)]

8

There are no hard fast rules, but my Paasche H’s work great at about 20psi and I lower the psi if I am painting in a small boxed in area of a model so the paint covers it well. The higher presures will tend to bounce the paint back out of small areas that have no outlet. The air presure is less critical on flat surefaces compared to detailed areas.

A double action type of airbrush normally uses a slightly higher presure since the air is controllable, unlike the H model.

9

Oh yeah, another thought. The higher the pressure the more turbulance it causes. This can blow away smaller parts and kick up or even suck dust into the paint booth.