Having slowly progressed with my first layout, I decided to dip my toe into airbrushing.
I would like to use acrylic paint and, to that end I have obtained some colours and a bottle of acrylic thinners  (Humbrol).
Would appreciate some guidance on the best way to proceed.

Thanks   Roger

not an expert at all but the best way to learn is to play. people talk about consistency of milk but that just confused me. I find I mix what I think looks ok then try it on a scrap piece of plastic pot. sometimes it runs or blobs and so needs thickening/thinning. I have found that the most important things are -

Item to be sprayed is clean
Airbrush is clean before use
I am just spraying into a shoebox at the mo but have a plan for a spray booth.
Work from beyiond your piece across it and stop the other side of it for a smooth layer
It is better to do several thin coats building them up rather than one thick lumpy layer.
Acrylic paint dries really quickly so additional coats can go on quite quickly after one another.

If you are going to mask for another colour, the undercoat is vital, recently had big patches of paint peal off with the masking tape when a stripe had been sprayed on, aaargh!!!

Anyway, I hope my ramblings help.

Most important point is to enjoy what you are doing!!

best wishes
Simon

i built a spraybooth from an old cooker hood (salvaged from a skip), large cardboard box for the booth, and some some spin-drier/ hood  vent tubing ) to vent the fumes outside

it works !

Sounds ideal. I am planning on using a clear plastic box with a bathroom extractor fan installed with a length of pipe to dump out the window.
Best wishes
Simon

Spookily, I have a question about acrylic paint too but not about airbrushing. I've always stuck with enamels up to now, but I have had to have a go at brushing with acrylic as this happens to be how the colour I want is available. Unfortunately, it doesn't spread, but instead stays where it is put and dries in blobs. I've had similar trouble trying to use proper grown-up acrylic when decorating the house but have had to give up and go back to oil-based gloss.

How do I get acrylic to dry flat?

Cheers,

Chris

Just my own experience - take it or leave as you wish:
Vallejo produce a range of pre thinned acrylic paint called Model Air. I find even that needs thinning down a little more, and I use their thinner. Different brands of acrylic paints seem to require different thinners. I've found some thin with just water, some with IPA, but some coagulate with IPA. Vallejo have their own thinner and I've not really worked out what it is made of. They also do a range intended to be applied by brush, but that thins down fine to be used in an air brush. I went on an air brush course - the training was on old tin cans (with label removed!), learning how to paint them nicely. Enamel paints are easier to use with an airbrush and easier to clean, but are less good for you and take longer to dry. The big issue with acrylic paints is keeping the airbrush clean. Once the paint dries inside the works it is a pain to clean. Enamel paints take longer to dry in the brush and are easily cleaned by flushing thinners through. For acrylics there is all sorts of advice on spraying water through the brush into special bottles or into your spray hood. My own technique is to have a large bucket of warm water by the spray booth. When I finish painting I stick the whole brush under water in the bucket and press the air button hard. This flushes large volumes of water through the brush, and because of the large volume of water the slightly painty output of the brush really doesn't matter.

I like the bucket of water idea if it works, I might try that. I usually put some airbrush cleaner through immediately after using. It is handy if you can swap paint containers on the brush for a quick change.

I usually wipe out the residual paint in the cup with a paper towel, dunk the whole thing in the bucket (hence the warm water, otherwise it's unpleasant on the hand) and then press the button. It bubbles away merrily. Then I take the cup off (it is bottom fed) and repeat. I then clean off the residual mess with a cotton bud. With acrylics I find speed from last bit of painting to bucket treatment to be key. Don't give the paint much of a chance to dry. Before I put the brush away I do run a bit of airbrush cleaner through, as it is supposed to keep the washers in good condition. You end up with a thin film of paint floating on the top of the water.

Well although I don't profess to be an 'expert' I do have a lot of experience painting and airbrushing models as well as figures. I find the key to using acrylic paints well is using a bit of retarder (Tamiya makes a good acrylic one) in the mix, as this allows the paint to slowdown its drying time and level out more. I have also recently started using the AK range of 'Real Colors' (Acrylic Lacquers) and they go down really nicely.

In terms of pigment levels in acrylic paints, they vary by make. I find the good ones to be Scale75, LifeColor, and Andrea. The AK and AMMO/MiG ranges are extensive but they do require a bit more work, as the pigment isn't as intense.

I gave up enamels and lacquers years ago, as the smell was just too much. FYI, the AK range of 'real colors' that are billed as acrylic lacquers don't stink like traditional lacquers! I will never go back to using smelly paints and thinners.

In terms of usage, there are literally loads of 'how to' vids on YouTube about how to effectively paint using an airbrush. The key is indeed practice, practice, practice!