How to get started in airbrushing

18 October 2018
Boxed-Airbrush-35699.jpg An airbrush is a useful and versatile tool, with lots of uses in railway modelling. This tutorial shows you how to use one.
A few basic skills with an airbrush can go a long way, with multiple applications in railway modelling. Follow our advice to start using this useful tool on your layout

If you can use an aerosol can, you can use an airbrush. The two work in the same way, but the airbrush offers a finer spray and more precise control.

 This tutorial uses a double-acting airbrush, which is suitable for novice and intermediate modellers. The double-action is important, since the same trigger controls the paint and air flow. Push it down for more air, or pull it back for more paint. After a few minutes messing around this all makes sense.

 You will also need an air supply. Aerosol cans of compressed air are options, but a compressor is better. There are plenty on the market and most will do the job. Safety is also a consideration. Paint fumes are toxic, so buy a suitable mask – one rated for vapour, not just dust – and always work in a well ventilated area. Enamels or acrylic paints can be thinned and sprayed, although practise will be required to ensure the right consistency. Mix it in pots and always mix a bit more than you think you need.

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 Finally, don't use latest locomotive for your first project. Dig around under second-hand tables at shows for tatty wagons. There isn't a painter out there who doesn't still practise on an old model or two so they can see how the latest mix or technique will work out.

Okay, let's look some basic airbrushing skills, then we'll see how it can be used for wagon, building, track and locomotive weathering. 


The Basics
In a typical kit you'll find the airbrush, a few accessories, instructions and a cleaning brush. This airbrush is set in double-acting form, but it can be converted to single-action using the supplied valve.
How to use an airbrush railway modelling typical kit


An air supply is essential. Aerosol cans of air are not really useful unless you need to work portably. They don't last very long and the pressure supplied drops off. Standing the can in warm water helps to even this out a bit.


The choice of compressors can be bewildering, so talk to other modellers and suppliers for suggestions. Left is a cheap diaphragm compressor that is noisy but effective. The other is a Sparmax unit that is quieter, more sophisticated and does everything your likely to require.
How to use an airbrush railway modelling compressor


The accessories you'll need are paint mixing cups (we used pound shop shot glasses), a stirrer and pipette for transferring paint thinners from the big bottle to the cups, and lots of kitchen towel.
How to use an airbrush railway modelling accessories


A mask stops you breathing in paint fumes. Do not rely on a dust mask, as these won't stop the much finer vapour droplets. Work outside if you can, using a large cardboard box as a spray booth.
How to use an airbrush railway modelling wear a mask


It might seem obvious to suggest how best to hold an airbrush, but we find this basic position is ideal for precision and control.


Mix up some paint 50:50 with thinners and load some into the airbrush. Then spend time spraying bits of paper to see how more/less air and paint mixes appear. Raiding the recycling bin for old plastic packaging isn't a bad idea either to practice on odd shapes.
How to use an airbrush railway modelling mixing paint


Learning how to mix paint takes a bit of time. Here, there is a bit too much thinners in the. We are aiming for lots of thin coats rather than a few thicker ones, so this isn't an issue. A hair-drier speeds up the drying process and reduces the urge to lay on a thick coat.
How to use an airbrush railway modelling applying paint


Wagon Weathering
More than anything else, we use an airbrush for weathering models. It's the only way to lay down a nice hazy colour over a surface and the results will generally look better than anything you've done before. The paints are thinned with white spirit at 75:25 thinner:paint.
How to use an airbrush railway modelling wagon weathering


Start with black, working from above and on the upper sides. The nozzle is held about 30cm from the model while working. If it's a warm day, the paint dries slightly before hitting the side giving a little texture to the finish. If it's cold, a hair-drier is useful between coats.
How to use an airbrush railway modelling wagon weathering applying paint


Bringing the nozzle too close to the model or over-thinned paint can cause runs. A kitchen towel moist with thinners is useful to quickly remove faulty paint. Another advantage of an airbrush is shown here, painting under the walkways is much harder with a brush.
How to use an airbrush railway modelling wagon weathering painting advice


Work the earth colour into the underframe by spraying from beneath. Start on one side of the wagon and bring the airbrush across making sure you go past it. Several passes may be required to build up the level of grot required. Finish with a coat of track colour. Don't worry about letting each colour dry before moving on, they can blend on the model just as in real life.
How to use an airbrush railway modelling wagon weathering advanced techniques


Adding a bit of dirt takes less than five minutes but the difference between clean and weathered wagons is huge. If you have a trains-worth of models, airbrushing a batch speeds things up. Being able to vary the colours adds a subtlety that can be missing from some factory weathered finishes too.
How to use an airbrush railway modelling wagon weathering finishing up


Building weathering
Ready to plant buildings, such as this Scenecraft Pendon Wash house, look great. For some reason the chimney is squeaky clean, which is not a good look at all.
How to use an airbrush railway modelling building weathering


Mix some black and dark grey paint, add thinners and gently spray around the chimney pot and nearby roof to add realistic soot. Build the effect up gradually depending on the area your model is set. The method works just as well in scratch-built and card kit-based models.
How to use an airbrush railway modelling building weathering mixing paint


Track weathering
Correctly thinned, you can airbrush with any paint you like. For this piece we used paint from the Lifecolor Rail Weathering set. While it is possible to thin these with water, a better result is obtained using the correct thinners.
How to use an airbrush railway modelling track weathering


Start with a general coat of ‘Sleeper Grime’, since this is supposed to be a grotty siding. Work along both sides of the track as the rail causes a clean ‘shadow’ to form. Pay attention to the prototype too – steam and diesel tracks get dirty very differently.
How to use an airbrush railway modelling track weathering painting


A mix of ‘Weathered Black’ and ‘Roof dirt’ is applied where a diesel loco has been standing. Once spraying has finished, rub the edge of a wooden lollypop stick along the rail tops to clean them of paint.
How to use an airbrush railway modelling track weathering adding details


Painting a locomotive
Start by spraying all the nooks and crannies. The chimney and dome are worth painting at this point too. We're holding the model on a sprung metal paint handle, but a piece of wood and Blu-Tack will work. Don't try to hold it with your fingers.
How to use an airbrush railway modelling locomotive weathering getting started


Cover the sides by starting the paint with the spray past one end of the model. Bring it along at a constant pace until you pass the other end. Repeat until the coverage is complete. Remember, many thin coats are better than one thick one.
How to use an airbrush railway modelling locomtive weathering paint masking


With a little practice, a good quality paint finish is within the reach of everyone. More complicated liveries are harder, but by this point you’ll need some of the many books available on the subject.
How to use an airbrush railway modelling locomotive weathering advanced


One essential chore is cleaning the airbrush after use. The paint is sprayed through a hole less than half a millimetre across, so if any is allowed to dry inside, it gum things up. Start by running the appropriate thinners through the airbrush until it comes out clear. Then repeat using airbrush cleaner. Put a cloth over the end to bubble the cleaner a little as part of the process. If things do gum up, the tool can be taken apart following the instructions and cleaned with cellulose thinners.
How to use an airbrush railway modelling cleaning up