Pressure for airbrushing

[Stevekir]

Based on advice from you folks (many thanks) I am having airbrushing success with 20 psi and thinning Villejo Model Air at about 15 to 20% thinner, 0.4 mm nozzle. I have asked Harder and Steenbeck some questions about my AB and amongst other things mentioned the pressure of 20 psi. They told me "By the way, your air pressure is way too low. Around 2 bar is recommended." 2 bar = 29 psi. Any comments on their advice?

 

[phalinmegob]

dont use vallejo yet steve but i spray at 15-18 psi using tamiya and revell acrylics and sometimes have to turn it down a bit for close up work. when i first got my new compressor with a guage on it, it was set at 30psi and this was way too high as i had spiders painted over everything. mind you i have learnt to control the airbrush a little better now.

 

[Roobarb]

Hi,

Everyone to their own but I'd have thought 20 psi was on the high side for airbrushing.I would of thought 30 psi would of allowed you to blast neat paint through the brush,I tend to use between 10 and 15 psi depending on paint type and what I am doing.One thing I've noticed is that quite a few people use airbrushes as sprayguns,spraying at distance not close up,high pressures limits your control of the paint flow,you may also run into issues of the paint part drying before it hits the models surface giving a rough finish.

Giving a fixed ratio of paint mix is also problematical as paint “thickness” varies tin to tin and thats not counting the difference between the various paint manufactures.The old description of paint requiring to look like skimmed milk for airbrushing is not far from the truth.When I thin paint for airbrushing I look to obtain an almost ink like run down the side of the mixing container.This afternoon I was spraying some Xtracolor PRU Blue I would guess I was using around 60% thinners (OK this is an enamal) I use WEM and Xtracolor enamels and as for acrylics I use Tamiya Polyscale and Gunze I start at around 30% thinners then normally adjust up as required,I appreciate this is my view but it works for me others no doubt have different approaches.

Malcolm

 

[Buttonman]

I only use vallijo model air and have never had a problem, I don't thin it and i run my compresser from 8 to 35psi all depends what you want to atchieve low psi close work nice fine lines higher pressure for bigger projects and special effects.

The most important thing is to keep your AB spottless, I'd also try .4 nozzle is a massive hole.

I use an Iwata CR with .2 conversion from John.

Hope this helps

Martin

 

[Stevekir]

I think I'll stick with 20 PSI (or possibly lower) because that works for me.

 

[tecdes]

Steve

Your most important point of call is Vallejo if you are using their paints. Downloads. This will give you overwhelming information &answers to everything. They will say 20 to 25 psi etc.

But your own experience from experiement will give you the answer so I would forget all the PSIs thrown at you. There is no clever index of PSI settings.

All of these will effect your use of the airbrush.

Thinning of paint

Nozzle size

Distance from the brush to the model

Temperature

What finish you need

Colour of paint (some airbrush better than others)

How much you pull the trigger back to release paint

Vallejo varnish works better for me on 20psi & with a .4 nozzle size.

You will read many opinions as to which PSI. But these are based on the above & what suits each of us.

The higher the PDI the more paint is going to disappear through the nozzle & vice versa.

From my point of view I have not used above 20 psi but adjust depending on a combination of the above. I range between 15 & 20%. But have found that the amount you pull back that trigger the most important part of the whole process.

The only way to reach a conclusion is to experiment & find in certain conditions & combinations which is better for you.

I have spent many sessions just experimenting with an empty plastic drinks bottle which pays dividends.

Laurie

 

[Roobarb]

Steve,

I miss read your original post I didn't see that you were using Model Air in that case you would not need to thin to the extent I indicated.I have to say I played around with Valerjo paint and ModelAir when they first became available which I guess must be ten years ago it might even be longer,I must admit they were not to my taste but each to their own.I agree with Laurie play around with your airbrush by practising on a scrap model or a plastic container. I've been airbrushing for around thirty years and I am still learning.

Good luck

Malcolm

 

[Caledonia]

Steve, I never worry about air pressure. I have a QR Air Valve fitted at the airbrush ( https://airbrushes.com/product_info.php?products_id=20652&osCsid=ccf3d5326515dd78bdba039c4101016d ), so I crank my compressor up to 35 P.S.I and use the needle valve to adjust the output until I am happy. Cheers Derek

p.s. also have one of these fitted to the airbrush https://airbrushes.com/product_info.php?cPath=1_9_52_63&products_id=1425&osCsid=ccf3d5326515dd78bdba039c4101016d

 

[andygh]

12 to 15 for me when I'm using Model Air, don't usually thin it at all

If I was set at 30 I'd get through a bottle of paint every 5 minutes, the walls would look pretty thougth