Monday, 6 August 2012

Airbrushing 101

As promised, I'm going to try and document my experience so far from a novice's perspective.

Equipment
The items I purchased are;
Compressor & Tank - Low entry price, recommneded on a few forums which I checked
Airbrush - Low entry price, spare nozzles/needles make it a versatile brush
Windowlene (Windex) - Recommended on a few websites as a thinning agent for citadel paints
Methylated spirits - To clean the brush at the end of your session
Stockings (yes really) - to strain the paint through after mixing, before it gets to the airbrush to reduce chance of clogging from large clumps of paint etc
Airbrush cleaning pot/holder - somewhere to spray cleaning fluid without inhaling it all
Cleaning tools - to remove blockages and clean the passage between paint holder & nozzle
Dust masks - some fumes from the methylated spirits will give you a headache and then some. Be careful with airborne alcohol/chemicals

Basics
Anywhere you look, you're likely to be told that the diluted paint mixture you are about to spray should be as thin as skimmed milk.  This is pretty much the mix I go for, and it's been fine when I've used it, in my limited experience.  It's easy to go too far on the watery side which can be an issue when the paint runs away when it hits the model.  It's easy to get used to however as you get more practice with mixing & painting.  Some paints of course require more/less thinner depending on paint quality/pigmentation etc.
I use a 50:50 mix of windowlene & water which I then mix paint into as necessary, usually 50:50 thinner mix to paint. By starting with the thinner mix, I can gauge how much paint I will need in total for the job in hand.
This is all then strained through the fabric into the airbrushes holding pot.

The PSI used in the brush is a difficult one to guide.  I used a lot of the advice in the No Quarter airbrushing article (41 I think), and this worked well for my first few sessions.  It seems to me though that the psi depends on a whole heap of factors such as consistency of paint, distance from painting surface etc.
As a rough guide though, when base coating, I use a higher psi (30+) and have the brush a fair distance from the model (maybe 10+inches) ans use wide sweeping 'strokes', bearing in mind that multiple passes is better than soaking the area in paint in one pass.
For a more controlled paint application, I've had the psi as low as 8-12 and had the brush very close to the surface.  this gives a great control of how/where the paint hits the surface, as well as being very responsive when pulling the lever back for paint volume

Findings
My first use with the airbrush (apart from being pretty daunting) was relatively smooth.  I connected the air hose between brush and tank, turned it on and let it build up to pressure pressure, filled the resevoir with the Vallejo Grey primer I had bought, and away I went.
I didn't photograph this stage, as it's pretty straight forward.  I've been poring over YouTube channels (mainly this one as it's amazing)  so I had at least a vague notion of how it all works.  No Quarter magazine#41 also had a small section on airbrushing, so I had a clue about psi/distance from model for the basecoat stage.

After my first victim (the poor high-elf spearman I have as a paint experiment, who has been stripped and re-painted more times than I care to recall), I decided to take the plunge and coat Maelok, and his Gatorman Posse.  Again, this went off without a hitch, in places the paint would pool, so I quickly move on, and try to keep sweeping the brush instead of holding it in place.  The paint/air mix lever is a tricky beast, and I should have practised a little more before trying "real" models with the process, all in all though, I'm pleased with the coverage, and the process.  It gives a lot better control and paint coverage than spray primer, and the grey base colour makes colours a lot more vivid than my standard black.

Next step was to get some base colours down on the Gatormen.  This was where it got really interesting.

Basically, my paints are old.  Old, and crusty.  It seems that not even straining them through the fabric could remove all the lumps/clumps that clogged my brush.  I didn't notice this at first, it having been the first time I mixed my own paint (the primer is brush ready) but I was having to pull back pretty much all the way on the flow lever before anything would come out, this of course meant that the paint was coming out way too fast, and I was getting pooling and the air pressure was blowing it all over the place.

I was pretty disheartened by this, and packed up after  I had used all the paint in the reservoir had run dry. It was only when I was cleaning the front part of the brush after removing the needle that I saw the material which had been blocking the brush.  Of course, I was relieved that the equipment wasn't at fault and I was eager to have another go the next chance I got.

The next time I had time to use the brush, I laid down a lighter colour on the front half of the model, and a lighter model still on the stomach/throat.  I was really pleased with how this came out, as gradiating colours is something I've never managed to do well with a bristle brush.  It re-iterated the (lack of) quality and (stupendous) age of my paints though, as I had more blockages again this session.

Findings
The upshot of all this is pretty simple. New paints.  I've been toying with the idea of replacing my ageing citadel line of paints for quite a while now, but could never justify the expense, especially when the paints I have are still usable (though just not up to scratch for airbrushing).

I've decided to pick up a few Vallejo Air Colour paints to use as base coats (black, white, dark brown, dark green etc) and replace my commonly used citadel paints with Vallejo Game Colour equivalents (which I'm told are the same paints as GW chemically, just without the re-branded name).
My range of paints will of course expand over time, but the essentials will really make a difference for me at the moment.

As far as success stories go, the last time I sat down with the airbrush, I decided to give it a real test, with a large area to basecoat, and a few areas which needed a three colour gradient.  A friend of mine left a piece of scenery at my place, so I checked if I was ok to paint it, and off I went.




I'm really pleased with how it all worked out. Nice smooth base coat, good coverage, and I think the highest highlights look fantastic, and it's all blended together well.  I dropped the psi to ~10 for the lightest colour, so I could get in close and be precise.
It isn't much, but for a practice piece, and an alternative to pretty much drybrushing the whole thing I think it looks good.

Sorry for the wall of text, but hopefully it will be useful to anyone starting out, or thinking about airbrushing :)
I'll try and post some more along this theme as I get more experience & results

Thanks for Stopping by
Lofty

4 comments:

  1. Very useful post.

    The gators and the skull look great - I recon I may just copy your load out as Im dead keen to get started with an airbrush.

    Look forward to seeing some more of your work in progress. :-D

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  2. Thanks man, I'm really pleased with the results. something I've not added to the above (but will in airbrush 102 maybe) is that you will need PTFE tape for all the joins between compressor, cable and brush, to reduce leaks etc. the compressor also runs hot, so don't be surprised by this!

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  3. "Basically, my paints are old. Old, and crusty."

    They aint the only things that are! Whoooo! Good too see you back to blogging, been looking at an airbrush myself actually so shall be following closely.

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  4. Snap :p I am particularly old & crusty...
    more to come mate, we are long overdue a game so hopefully you'll get to see the results first hand soon enough

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