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Hi guys !

I am a newbie in the world of airbrushing, and I have read many things about technique, how to use the airbrush... but I have a question concerning the paint.

I must dilute my paint with a thinner. I have choose a 15% isopropyl alcohol solution. I would try a ratio of 1 part of paint for 5 parts of thinner to begin with.
I have also read about a Fluid Medium, and have find a Medium Mat from Liquitex. The purpose of this product is to help the pigment of the paint to disperse well.

My question is : How much fluid Medium should I use, and to I add it it my paint : before or after having added the thinner ?

And for sure, all your advises will be welcomed

Thanks !

Liquitex offer an 'airbrushing medium' as part of their range of acrylic mediums, its pretty handy, can be used in any ratio with acrylic paints. Because its an acrylic binder in its own right, it will not destroy the paint film's surface tension like over thinning does very quickly to acrylics, particularly with water.

If thats the medium in question, then any amount... it totally depends on how strong you want your colour to spray vs how thick the paint being thinned is. For a very subtle effect you could use mostly medium in the mix, but for getting the strongest colour possible you will need to be a bit more careful about adding a minimal amount to achieve the viscosity you want for spraying. Which again depends on what you're intending to be spraying; freehand detail work with an airbrush actually requires severely over thinned paint. Have you seen the custom car and motorbike airbrushing that gets done, the detail achievable with airbrushes is incredible, technically the brush can spray a line of comparible width to its nozzle... so thats what 0.3mm on your average brush.
For getting coverage with a colour, for example basecoating a mini you will wnat the paint to retain a strong colour and high amounts of coverage, so minimal thinning... just enough so it will atomise.
You should not need the thinner with the acrylic medium, but you can still use it; I would mix the paint and medium together first and then add thinner if its still not as thin as you want.

I use 2/3 Matte Medium, 1/3 distilled water and one cap and a half of flow-aid to create the thinning mix.

After that I dillute appropriatel depending on which paint (GW, P3, Vallejo) I am working with.

I've started to use Vallejo Air, paints tgat gave already been thinned, great stuff!

Thanks for your tips, gonna try that as soon as rain would stop


Automatically Appended Next Post:

I use 2/3 Matte Medium, 1/3 distilled water and one cap and a half of flow-aid to create the thinning mix.

After that I dillute appropriatel depending on which paint (GW, P3, Vallejo) I am working with.

And what is the ratio paint/thinning mix you use with GW paints ? I have read 5/1 and I think this is to much dilutate ?

The 'correct' thinning ratio for any paint to be sprayed, depends entirely on the paint itself, its viscosity, pigment sizing and density, the environment you want to spray within, what kind of effect you want; solid coverage, transparency, ultra fine detail, subtle blends all work best with differently prepared paints.
To ask us for an exact formula on how to thin your citadel paints is a bit un-answerable.
Using the matte medium / water + flow aid mixture suggested above you will certainly run into an issue where the paint film surface tension is destroyed by the amount of water within the mix so care has to be taken to not over thin with water.
Solution to this is to use thinner acrylic binders, such as the airbrushing medium I mentioned. Which will allow you to reach much lower viscosities before the paint is utter crap than using water.
This question is asked a hell of a lot... and there is no right answer. Any answers you might get are going to be just what other people are doing for the effects they want to achieve, in their own personal environments with their own preferences of paint brand etc. and not guaranteed to work for you.
The best thing to do is to take everything said with a pinch of salt and apply some thought, then try some things out for yourself based on suggestions from others you can follow the logic of. Theres many many ways to get paint spraying through an airbrush and no ones technically wrong here.

 meecham63 wrote:
Thanks for your tips, gonna try that as soon as rain would stop


Automatically Appended Next Post:

I use 2/3 Matte Medium, 1/3 distilled water and one cap and a half of flow-aid to create the thinning mix.

After that I dillute appropriatel depending on which paint (GW, P3, Vallejo) I am working with.

And what is the ratio paint/thinning mix you use with GW paints ? I have read 5/1 and I think this is to much dilutate ?

Roughly but it can vary from color to color.

If you are trying to thin a GW "Layer" 3:1 or 5:1 ratio is good.
If you are trying to thin a GW "Base" you might have to go 8:1 as those tend to be thicker and can clog an airbrush real fast. Something else I might try in the near future is 5:1 but add 2-3 drops of flow aid and see if that helps.

Also the mix I mentionned is for a 600-700ml bottle of thinner mix. If you put a cap and a half of flow aid straight into your airbrush it's going to flow...BIg time...probably too much.

I would suggest using actual "airbrush medium" either the liquitex or I personally prefer the "golden" brand.

As to the amount to thin - its the amount necessary to get the coverage you want at the pressure you are using.

Which, just as others have commented, is completely subjective.

For example, if you are using a large needle (.25) and spraying a large area (and thus high psi) you will need less thinning.

If you are using a smaller needle for detail work (.21) and less psi for more control, then more thinning.

Make sense?

A good rule of thumb is "thin to the consistency of skim milk" which is still..subjective.

Check out some of the various airbrush videos on youtube, specifically buy painted and awesomepaintjob. There are many more.

Regarding pre-mixed airbush paints - I love them.
I use vallejo model air, createx, minitaire and golden.

The most important thing in this craft (it is indeed an art to get good at it) is to practice - experience with your brush and your paints is the most important thing.

See if you can find a friend who has various paints for you to borrow or see their set up. If you live in the DFW area, send me a PM, I would be more than happy to help.

best of luck and enjoy the airbrush!