Painting: Airbrush 101

[winterdyne]

Thought I'd donate a little airbrush tutorial, in an effort to improve my writing. :-) I hope this is found helpful.

 

[NOTE] This is a work in progress. This first post will be updated periodically.

 

Please feel free to ask questions, point out anything I'm doing heinously wrong etc...

 

 

----------------------------------------------------

 

Airbrush 101 - Part One - Equipment.

 

This part of the tutorial is aimed specifically at those completely new to the idea of airbrushing, particularly using a dual-action airbrush. I'm being quite specific with the kit I use, although most people will probably have quite a similar setup.

 

The key to successful airbrushing is preparation, and knowing your kit. Here's what I have on my desk before starting an airbrushing session:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig1.jpg

 

1: Airbrush holder. Firmly blu-taked to the table. This is essential to put your airbrush on without spilling paint from it.

 

2: Drops tray. For emptying the cup of the airbrush before carrying it over to the sink to rinse it out. Also for dumping q-tips used in cleaning and other general crap you don't want lying around.

 

3: Airbrushes. I currently use a Revell DB-750 profi-plus draw feed dual action and a cheap AB-130 gravity feed dual action from EverythingAirbrush (an absolute bargain, and a lovely brush, which I'll be using in the tutorial).

 

4: A wet pallete. Used to hold paint I'll apply by brush at points. Helpful in judging mixes to use.

 

5: 1ml syringes and a pipette. The syringes are used for handling paint, and the pipette purely for thinners and water.

 

6: The models in question. Having them in front of you helps you plan. In this case we have a rhino I've just preshaded, and one which still needs the treatment.

 

 

Familiarity with your equipment and how it works is important, too. Here's the AB-130 in more detail. It has many features in common with other more expensive dual-action gravity feed brushes:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig2.jpg

 

1: Needle cap. Internal mix airbrushes (ones that mix the air and paint inside the body of the brush) work by drawing the paint along a needle to the nozzle. This cap covers the needle and can be removed for very close work. It is important not to damage the end of the needle as this can lead to spatter.

 

2: Paint cup. In gravity-feed brushes like this, the paint is stored in a chamber also containing the needle, and gravity pushes it down. Also, with the cup being above the body of the brush it's easier to add paint to it on the fly (ie whilst there's still another colour in it), which is very useful in preshading and blending techniques. The mix of paint is important - you need to use very thin paint (about 4 : 1 thinner : paint at minimum), as is the choice of thinner - for close work a quick-drying medium will help avoid runs and too 'wet' an application, at range water is ok, as is a future/klear and water mix.

 

3: Trigger. Push it down to make air flow through the brush and pull it back to draw back the needle, allowing more paint to flow through the nozzle. The technique is to get air to flow first (point away from your work to throw off any spatter) then point at your work, let the air flow first and then gently pull back to increase the paint flow. More pressure down on the trigger allows more air to flow, as does having a higher output pressure set on your compressor (see later).

 

In general:

 

High pressure + high paint flow = large spray pattern, best at distance, with slow-drying paint (water medium rather than iso-alcohol (eg Tamiya).

Low pressure + low paint flow = very small spray pattern, best at very close range with a quicker drying medium (alcohol based).

 

4: Air inlet. This is where the hose from the air source connects to the airbrush. Be aware that you'll have a dangling pipe under your hand that can potentially catch on things.

 

5: Action limiter. This is a screw-stop that prevents the trigger from being pulled back more than a certain distance, and is useful for limiting the spray to a small area.

 

Okay, now we need to talk about air sources. Give up the propellant cannisters - they're expensive. I use a machine-shop compressor. It's loud, but has a big tank. You can find smaller, quieter compressors, but you'll also find an increasing price in line with the convenience. There are a few extra things you need too:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig3.jpg

 

1: Output regulator. You don't want your pressure to be reliant on what's in the compressor (or it'll be running all the time, loudly). This controls the flow of air into the hoses for the brushes and closes when the required pressure is reached. For most purposes, you'll be wanting a pretty low pressure - I use around 15-20 psi. For varnishing and large area work, crank it up to around 25.

 

2: Isolator. You want to be able to stop the flow of air to the hoses so you can disconnect brushes to clean them without venting the tank.

 

3: Moisture trap. When you have air under pressure escaping, it's cold, and this causes any water vapour in it to become liquid quite easily. Obviously this will effectively add water to your paint. This little chamber catches any condensate coming out of the compressor.

 

4: Pressure release valve. On the other side of the isolator, this allows you to remove the pressure from the hoses, allowing you to disconnect your brushes without escaping air causing the hoses to buck.

 

5: 1/16" nipple. For small (badger standard) airbrush hoses. In general you'll need one of these to connect your airbrush to a standard compressor.

 

6: 1/8" nipple. For larger airbrush hoses. The fun I had finding one of these locally after forgetting to order it along with my airbrush...

 

Now, getting ready to start - we have our airbrushes in the holder...:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig4.jpg

 

... and importantly, the hoses are not tangled - you don't want to be pulling the other brush around while painting (especially if it has paint in it!):

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig5.jpg

 

Coming up in part 2 (should be later today), we'll take this flat DA green Rhino:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig6.jpg

 

And turn it into something looking like this, ready for detailing, metallics and weathering:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig7.jpg

 

End of Part 1.

 

 

 

 

Part 2 - Preshade Airbrush Work

 

We start by putting some water into the cup:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig8.jpg

 

Then a few drops of flat black paint:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig9.jpg

 

We mix it up with a paintbrush, should look something like this:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig10.jpg

 

Test the consistency on a piece of paper with both the brush...:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig11.jpg

 

 

... and the airbrush. ALWAYS test spray before each pass on the paper, not the model. This avoids unexpected spatter, and helps you get a good feel for the spray pattern you want. In this case, we want a pattern that's about 4-5mm across, and fairly translucent:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig12.jpg

 

We spray the black over all raised edges (where you'd think of putting an edge highlight) and into deep recesses. Spots are sprayed onto individual rivets that we want to define sharply.

 

Don't worry too much about neatness, as the filter and highlight coats will tidy things up. This said, you do not want runs (dribbly paint) to occur, so make use of the practice paper before you point the brush at the model to get a feel for the distance you need to hold. The effect you want is for the paint to go on looking moist, but to appear to dry almost immediately in the airflow. I took around 15 minutes to get to this stage.

 

This will look very harsh at this stage, but it will be toned down:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig13.jpg

 

Clean out the brush, and this time put DA green into the water. Mix it up with a paint brush...:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig14.jpg

 

...check the consistency...:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig15.jpg

 

...and test spray. We want a slightly larger spray pattern this time. Again we want to have a feel for the correct distance to avoid runs:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig16.jpg

 

We apply a gentle filter coat from high angles (down towards the model, with the model upright) and also concentrate on the centres of large panels to brighten them. Large areas naturally reflect more light than small, so the observer's brain expects them to be brighter. This gives a small model the impression of being bigger:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig17.jpg

 

We repeat this process a couple of times, each time adding a little Snot Green to the mix along with a few drops more water:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig18.jpg

 

Here you can see the consitency check for the third time - note that by putting a test stroke on the white paper we can immediately see if the mix is a brighter green:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig19.jpg

 

After the two highlighting passes (taking maybe 20 minutes), with the airbrush we have this:

 

http://www.winterdyne.co.uk/maz/images/airbrush101/fig20.jpg

 

All that remains now is a light drybrush with Snot Green on the edges and rivets and to paint the metalwork black.

 

End of Part 2.

[wiplash]

nice can this be done with crappy airbrushes?

 

can you post an accurate ratio for water to paint?

for say:

GW paints

GW inks

 

<_<

that would be great

[winterdyne]

I'll be doing a full tutorial on paint mixes and cleaning the airbrush (declogging), but it's really down to what your particular airbrush likes. Start with around 4 or 5 : 1 and if it gunks up thin it some more. There are various other things you can add to the paint (flow improvers, solvent thinners, future/klear) etc, again these are often down to personal taste. With Citadel and Vallejo paints I've had reasonable results with plain water.

 

As for 'crappy airbrushes'? I dunno. I haven't got one. I might pick up the GW one (as I think a lot of newbies will) in order to put together a tutorial on using it - but the AB-130 I use is less than £30, and is frankly a much more flexible piece of kit once you put in the practice.

[Karitas]

I have the AB-130 too, was the first one i bought and its wicked for large areas.

 

i found it a little frustrating for very fine detail and now have a badger for that purpose.

but for vehicles that ab-130 will do incredible things for 30 quid.

[winterdyne]

Odd, I'm finding it excellent. I can get a steady line at around 1mm diameter spray, which is fine enough to do preshading tricks on a marine's face. Which is what I wanted it for. The DB-750 is great for areas and has the advantage of a draw feed so I can jar up varnish mixes etc...

[wiplash]

http://www.hobbylinc.com/gr/bad/bad250-3.jpg

i have something along the lines of this (if noit that exact one) it is a badger though

is the ab130 worth getting? especially if i will be using it for art/graphics work as well as modeling

[Karitas]

http://www.hobbylinc.com/gr/bad/bad250-3.jpg

i have something along the lines of this (if noit that exact one) it is a badger though

is the ab130 worth getting? especially if i will be using it for art/graphics work as well as modeling

 

What you have there Sir, is an external mix single action airbrush with a can of propellant. this is about the worst airbrush you could possibly be using for good results :eek

 

an AB 130 and a cheap compressor will be streets ahead, as the ab is dual action internal mix

 

if it's for art and graphics too, you'll really see the benefit.

 

as to my issues with the ab, i think its more tha fact that because i have the badger, i dont try to get the best out of the ab, as it has a much larger reservoir i just use it for coverage.

 

i'll challenge my preconceptions and give it a chance to impress me ;)

[winterdyne]

Those external mix cheap airbrushes are ok for varnishing and basecoating large things - in fact you can save money by using future to varnish with one of these, but for preshading panel lines / doing anything fine or on the fly they're just not up to it. You can even do a basic zenital preshade with these by mixing up the tones in separate jars, and you'll realise very quickly why having the ability to mix paint whilst it's in the airbrush is a godsend. You'll also start yearning for the ability to have a finer spray pattern, which is when you'll want to start looking at dual-action brushes.

 

For varnishing:

 

Get FOUR jars. Fill one with future / klear, one with water, one with windowlene or weak ammonia solution (about 20:1 water: cleaning ammonia) and one with 'flat future' - a mix of about 7:1 future : Tamiya Flat Base.

 

First coat - gloss - neat future / klear. Spray with a fine mist (not too close) to avoid runs and dribbles, keep the spray moving. Clean brush by spraying through with water then windowlene. Allow to dry in a DUST FREE area. Apply decals at this stage (and then gloss again to protect them).

 

Second coat - matt - use the flat future, again this will go through neat, and clean the brush with water, then windowlene. Allow to dry in a DUST FREE area.

 

For zenital preshading:

 

Mount miniature on a handle or block.

 

Prime miniature BLACK and allow to dry. Depending on the overall tone you want the miniature to have mix up 3 or 4 tones (read up on colour theory - generally you'll be wanting an increasing amount of a buff / khaki / bone to represent yellowish sunlight).

 

Spray the darkest tone lightly over the entire miniature from all angles, and slightly more from the light direction (usually taken as 45 degrees downward).

 

Spray the next tone and the next in turn lightly from the light direction.

 

Paint miniature using thin glazes to tint the existing preshade.

[wiplash]

an AB 130 and a cheap compressor will be streets ahead, as the ab is dual action internal mix

 

whats cheap? and with compressors is there a difference between cheap and crap?

something like this?

compressor 1

 

also is there a difference between paint airbrushes and the beauty ones e.g. nail and tanning etc as there seems to be a bigger market for the beauty ones (going on ebay anyway)

so then that opens up something like:

compressor 2

or even shock horror :D :

compressor 3

 

for those two i presume you can remove the spray gun that comes with it and replace with an airbrush?

then i stumbled upon this:

airbrush with compressor 4

 

is that a decent airbrush/compressor

thanks in advance

[Karitas]

:D

 

hokay, on compressor 1 theres very little information, i'd suggest emailing the vendor and asking him who the manufacturer / what the model is the use your search-fu to do a little research. (my main concern is that although it has a guague i dont really see a regulator)

 

I have one much like your compressor 2, the valve you can see where all the hoses are is the regulator, which allows you to change the pressure - you will need this feature if you get inot it, that said a regulator costs 10 quid and screws on.

 

compressor 3 is the same kind as 2, from what i can see. what are called "diaphragm" comrpessors, the use an ossicilating disc to create the air flow. i have heard some people complain about "spiky" air flow with this kind, and insist on an air reservoir, but as i say i have one and have never had an issue.

 

the last one there is pretty much a black box again, so without searching google i dont know a lot about it i'm sorry.

 

as far as the principles of "cheap" and "crap" i'd say your list of "wants" ahould be - 50ish psi, with a moisture trap and regulator, if quiet is important check those details too, they should be listed. a reservoir is up to you, i've never felt the need for one, but others do. and even buying brand new, about 60 quid should do it.

 

http://www.everythingairbrush.com/acatalog/AB-AS18-800-wide.jpg

this is the kind of thing i have, the moisture trap is combined with the regulator here, and the "knob" will allow you to set the pressure. it's motor will only run when you are using the airbrush, and they arent that loud.

 

i hope that's been of some help, and i'm sure the more experienced airbrushers will have some additions/corrections ;)

[Peakey]

How about the GW one? is that any good?

[Brother Argos]

As a simple spray gun for basecoating or undercoating its fine, but it is not really capable for more delicate work.

[stump]

The examples GW gives for there airbrush as Brother Argos pointed out is base coating. There is an article in the Lord Of The Rings sections about painting an army in a day. They use there airbrush as base coat only then paint details then wash them with GW washes. Good for quick army painting but not what winterdyne is trying to do or show you.

 

Very good topic I really like the way your using water as your mix, I was using an acrlic paint thinner and found it gave me more consistancy with mixing, but they quit making the type I was using and I am down to my last bottle. I will try your mix next time.

 

Question: The mix your looking for is it like skim milk with the water mix or even thinner than that? It looks in the pictures to be thinner but I am unsure.

[winterdyne]

Pretty much skimmed milk (ie quite thin). That said, I also use a home-made acrylic thinner / medium of about 3 parts water to 1 part klear / future.

 

I'll cover these (excluding anything expensive) in a future tutorial.

 

The GW spraygun is erm, a spraygun. Can't really call it an airbrush.

[winterdyne]

Can we keep the 'what do you think of [ebay item]' posts away please - ask via PM (some already have) or MSN if you need to, saves polluting the thread.

 

Can a mod also tidy up any that are existing? Thanks.

 

The ebay items I'm seeing (in the £70 - £75 range) are all OK looking to me. They're basically the same airbrushes I use. Please look at the first post, especially the 'equipment' bit. If the kit you're looking at has the same features then you're laughing.

 

If folks are going ahead with this and buying airbrushes and compressors, I cannot reiterate enough the importance of reading around. Don't just take this tutorial as gospel, google things like 'cleaning an airbrush' and read around the subject - especially pay attention to cleaning. Also read up on paint mixes, ventilation and safety requirements (citadel with water is fine indoors, but lacquers may need a respirator or at least a good filter mask). And cleaning chemicals.

 

Did I mention cleaning? A clean airbrush is a happy airbrush (and one you can use again).