It's been said that a good paint job can make a mediocre model into a superb one. It's also true that poor painting can ruin even the greatest example of the model-makers art. Because we all know this to be true, the finishing stages are approached by many with trepidation. Traditionally we've slapped on Humbrol with a brush, using techniques that haven't changed since our days building Airfix kits. Anything more advanced is viewed with suspicion or awe. To step up is scary and involves buying expensive equipment which we have to learn how to use. In this article I hope to demystify spray painting a bit and explain what you need and how to use the gear. First of all let me say that there is nothing wrong with paint applied with a brush. Care, good preparation and quality brushes will give results nearly as impressive as a sprayed finish. But you need to stop using the cheapo brushes and get used to paying four or five quid for a sable brush. Quality takes time too. If you slap the paint on and try to cover with a single coat you'll be disappointed. Many thin coats are the recipe for flawless paint and each must be left to dry fully in a dust free environment and then probably rubbed down before over-coating again.
Step 1: So You Want to Try Spraying?
One colour I always spray from a can is matt red oxide. The commonly available primer is just the right colour to my eye for below the waterline on many models. It's also very easy to use. As long as you shake the can for at least a couple of minutes (thorough mixing is essential for all spray paint) it's difficult not to get a good finish. Primer isn't waterproof though, so you have to consider a top coat of varnish to seal it in, especially on wooden hulls.
Step 2: Airbrush
Next up is a proper airbrush. For years I've used a Badger 200, a simple single action airbrush, for my railway modelling and it's also seen action on my boats. Single action indicates that the button on top simply controls the air. On a double action airbrush the control manages both the air supply and the paint/air ratio. To control the latter, on the 200 you turn a screw at the back end of the tool. This is fine for most work, but as you progress you might want the extra flexibility, and probably by that point though you'll have a far better idea of what you are doing. The basic airbrush will still have its uses, so it won't be money wasted.
The biggest problem with the airbrush is the relatively narrow spray pattern. When painting, the trick is to work along the model always keeping a wet edge. The sprays should overlap each other slightly for a seamless join. The spray guns wide spray pattern allows for fewer passes than the airbrush. I'll admit to spending many happy hours chasing over a modest sized model trying to build up a depth of colour with my airbrush and sworn I'll do all the painting in future with aerosols, but then I'm not the most patient person in the world.
When choosing an airbrush you need to think about how the paint is carried. Most models allow you to clip on a paint cup or bottle. The latter is needed for boats as you'll want to mix up whole tinlets of paint at a time and the cup is not big enough for this. Buy spare cups and plenty of bottles too. I'd also recommend a paint cup or bottle just for the varnish, to avoid colour contamination at the final stage.
Step 3: Air Supply
Oh, and car tyre adaptors. Yes they are available and yes you can run the tools off them, but do you really want the spare tyre from you car in the modelling room and do you really want to have to pump it up every five minutes?
A compressor therefore might look like an expensive bit of kit, but in the long run will pay for itself. In fact if you forget to put the tyre back in the car after a spraying session then the bruises you'll suffer from your passengers when you have a puncture will be enough to convince you. There are several types of compressor ranging from the simple diaphragm type which run continuously, are a bit noisy and give merely adequate air pressure, to huge jobs with reserve tanks which run intermittently to charge the tank when the pressure drops. Cost is between £65 and £350 with some bargains to be had at shows and on the secondhand market. At this point I'd talk to the suppliers and ask advice. All I can say is that I have two and most of the work is done with the cheap one. The only time I've needed more pressure was for a grit blasting gun.
Step 4: A Face Mask
Step 5: Masking Tape
Step 6: Airbrush Cleaner
Step 7: Thinners
Also useful are; paint stirrers, kitchen towel, paper for masking, turpentine or white spirit and cotton buds for cleaning out the tool at the end of the session. If using newspaper for masking make sure the ink will not come off on to the model.
Step 8: Paint Choices
For your first attempts find a suitable draught and dust free place to work. I use a bench in the garage because the door can be shut to keep the worst of the smell out of the house. Also, for test purposes, don't use the model you have spend months building. A cheap plastic bowl will do the job. Paint it with primer from an aerosol to give your top coat something to grip.
Once dry, mix up the paint and thinners. You are aiming for a consistency of milk but this will come with practice. Too thin is fine, it just takes longer to build up depth of colour. Test the airbrush with turps or white spirit on to some newspaper. Then attach the paint jar and spray some of this on to the paper until the colour comes through. Next start the spraying of the model or bowl and pass the spray over it keeping about six inches away. Once past, stop spraying. Then repeat, overlapping the last paint line. When you've finished the coat I like to warm the paint with an old hair drier so it dries before dust can settle. If you've over-thinned the paint do this and then put another layer on.
To be honest there is no substitute for practice. Things will go wrong, but you'll learn how to cope. One cardinal piece of advice if you get blobs or runs, leave them alone. Don't try and wipe the paint off with a cloth. Once dry, the excess can be gently sanded off and touched back in. Mind you, I still try wiping and I've just written this advice.
Once you are happy, clean the tool. First run turps though it. Then brush cleaner. Clean the orifices with cotton buds and more brush cleaner. Finally finish off with airbrush cleaner. As a precision tool, an airbrush benefits from a good cleaning and it's easier to do it immediately after painting rather than before a new session.
Spray painting is unfairly seen as scary. The truth is that if you can use an aerosol can, you can use an airbrush. The only difference is that you have to thin the paint yourself and in this article I have only scratched the surface of the subject. Others I'm sure will be happy to expand on other aspects such as fancy paint schemes for racing boats or weathering for working ones. Sadly there is a high initial cost, but after this the costs are tiny and much cheaper than buying lots of quality brushes!