Mixing medium for painting with airbrush

[Mistress of minis]

GW paints are kinda...bad, at being airbrushed. You'll have to experiment to get the right ratio as what works for one color will not work for the next (unlike vallejo & reaper which seems a bit more consistent between hte colors).

The size of the nozzle on your AB is also a factor with the thicker paints. .3 is about as small as I will even try for paints not specifically for an AB. For the really goopy stuff like the GW foundations stuff even a .5 can clog up frequently.

The general mantra for airbrush paint is 'consistency of milk'. An thicker and you get clogging, any thinner and it takes numerous coats.


Ultimately, experimenting is the name of the game, finding out what works for you, the brush you have, compressor, paints and mediums makes for a huge number of variables. Threads like this can help give you ideas where to start, but the fine tuning is up to you

[beno]

The general mantra for airbrush paint is 'consistency of milk'. An thicker and you get clogging, any thinner and it takes numerous coats.

I would say that the consistency of milk is a little misleading - I never thought it made much sense. When I started out airbrushing I'd try to make it milk thin, but it would end up spattering all over the place because it was far too thin!

I use mine for priming just about every model, with Vallejo's Surface Primer, and have found that one drop of water to two parts primer is spot on. This is much thicker than milk I think, but works perfectly!

Trial and error is the best way. My advice would be to start with one large drop of water in the cup and three large drops of paint and stir til its a consistent mix. Test spray on some paper; if its too thick (probably) add a small drop of water and stir it thoroughly in... keep adding water in small quantities until you can spray an even, smooth line. Now go paint your models!

[Regnir]

I would say that the consistency of milk is a little misleading - I never thought it made much sense. When I started out airbrushing I'd try to make it milk thin, but it would end up spattering all over the place because it was far too thin!!

It's not necessarily about how thin it is though, in your case. You can spray incredibly thin paint if the PSI regulator on your compressor can adjust well below 10 PSI.

I often times spray with an Iwata Custom Micron(model CM-SB) which is a .18mm needle/nozzle combination. I spray a mix of GW and P3 paints, and generally have to thin about 1 part paint to 15ish parts thinner(I use Windex or Testors Acrylic Airbrush Thinner, whichever I tend to have on hand). The trick to spraying this thin is to drop your pressure dramatically. I tend to spray at around 5 PSI with the CM-SB and 1:15 citadel paint. This is amazing for pre-shading 28mm infantry models, and even some vehicles.

For the majority of my work, I use an Iwata HP-C+, and almost always use a straight 1:1 thinning ratio. The HP-C+ is a .3mm needle/nozzle combination. I tend to pre-mix my paints in empty Vallejo style eyedropper bottles that I pick up from the internet in that 1:1 ratio, and then further thin them down in the airbrush cup just prior to spraying. Works out quite well.

Citadel Foundations and Metallics are a different story. The metallics I tend to keep thinned at 1:2 or 1:3 for a nice even spray, and Foundations tend to be closer to 1:5 or so.