Airbrushing for Beginners 3

1 - 2 Needle & Nozzle Cap: Serves a dual purpose of protecting the needle and directing the spray pattern. Sometimes the needle cap, which sits at the spraying end is combined with the nozzle cap just behind it.

3 - Nozzle: Sometimes called a tip or cone, the nozzle is one of the most important parts of an airbrush. Like needles, nozzles wear out over time and will need to be replaced. The nozzle is a very delicate component, and can easily be damaged beyond repair by feeding the needle through the airbrush too forcefully.

4 - Colour Cups: The Gaahleri GHAD-39 features two interchangeable colour cups, differing only in size. Each cup comes with an O-ring to ensure air and paint do not leak out of the cup’s connection point. Generally, I’d recommend just leaving the larger cup attached unless you know of a specific reason why you want the smaller colour cup attached.

5 - Colour Cup Lid: A metal lid that securely fits the colour cup via a friction fit. This prevents spillage, which you’ll want to avoid for two reasons: one is that it may stain whatever you spill on, but the more important reason is due to the smooth metal curves of your airbrush, the spilled paint will glide down, and flow along the bottom of your airbrush towards the tip. 

Please note: Because you are spraying at a downward angle, if the paint spills and glides to the needle crown/cap it will be propelled forward by your airflow (without being atomized within the airbrush) and spit all over your project. Or your hands. Or both. 

6 - Airbrush Chassis: The main body of your airbrush, which houses its internal mechanism and connects the whole shebang together.

7 - Packing Set: This is essentially a special-purpose O-ring and screw that prevents paint from flowing back into the airbrush past this point by creating a firm seal.

8 - Main Lever/Trigger: In a dual action system, the trigger has two functions. By holding it down it opens the air valve, letting the compressed air flow through parts 6-3-2-1 in that order. By pulling the trigger back, the mechanism moves the airbrush needle to allow the thinned paint to flow down through the aperture at the bottom of the color cup, mix with the air and atomize.

9 - Trigger Housing: Made up of the needle chucking guide and auxiliary lever. It sets the needle and “guides” it into the correct position, ensuring that it always moves correctly. The auxiliary lever allows more control over the back-and-forth motion, reducing the amount of movement needed to pull the trigger.

10 - Needle Spring: Allows the needle to slide back into place automatically, via the tension in the spring, which plugs the aperture when at rest and allows for better control of paint flow when spraying. Without this, one would have to manually move your needle back and forth. Springs lose retention over time and should be replaced when they begin to lose it.

11 - Spring Guide: This keeps the spring in the optimal position as well as secures all prior components in place via a screw, keeping the housing together.

12 - Needle Chucking Nut: A retention nut that screws on and keeps your needle in place. By gripping onto the needle via the rear of the trigger housing, it allows your needle to slide back-and-forth via manipulation of the main lever/trigger.

13 - Handle: A smooth section to aid in comfort while spraying and protection of the internal mechanisms. I generally leave this off while spraying depending on the job at hand. Uses an O-ring that keeps the handle airtight and secured. 

14 - Fluid Control knob: Most dual action gravity fed airbrushes include this knob. It attaches to the back of the handle, and allows you to manually set the maximum distance the needle can slide back, therefore limiting the amount of paint released while spraying.

15 - Needle: Extremely pointy and delicate. The slightest drop or careless accidental impact to the needle cap/crown of your airbrush may bend the needle tip. Sometimes you can gently bend it back into place, but this is easy to get wrong and will sometimes result in snapping part of the needle off. A bent needle tip, however infinitesimal, will affect the angle, pattern and quality of your spray. You cannot spray with a broken needle.

16 - Air Valve w/ Spring and O-ring: Manipulated by the bottom of the main lever/trigger pressing against it to release compressed air into the brush. The included O-ring prevents compressed air from leaking out of the air valve, ensuring it travels up into the brush for its intended function to deliver to correct PSI.

Before putting any paint into your airbrush, let’s learn how the trigger works.

Turn on your compressor. If you’re using a compressor with an air tank, give it a moment to fill and reach pressure. For beginners, a good starting point is around 18 PSI. There are plenty of reasons why you might spray at a lower or higher pressure, and most hobby airbrushing happens somewhere in the general range of about 15 to 30 PSI, but we don’t need to worry too much about that yet. For now, 18 PSI is a perfectly reasonable place to start.

If you’re using a tankless compressor, it will usually be ready to go almost immediately. Depending on the model, it may also have preset pressure settings rather than a traditional regulator.

Now take a look at how you’re holding the airbrush. The standard grip is similar to holding a pen, with your index finger resting on the trigger. Some people prefer to use their thumb on the trigger instead. There’s nothing wrong with that if you find it more comfortable.

Press the trigger straight down. You should hear air begin to hiss through the airbrush. If the airbrush is permanently hissing even when you aren’t pressing the trigger, that usually means the air valve is sticking and may need to be cleaned.

Now imagine that there’s paint inside the colour cup. While continuing to press downward for air, slowly pull the trigger backwards. The farther back you pull, the more paint the airbrush releases. That’s really the basic principle of a dual-action airbrush: Press down for air. Pull back (slowly) for paint. The key word here is slowly.

Airbrushing is mostly an exercise in control, patience and gradual application. You generally don’t want to slam the trigger all the way back and flood the surface with paint. Small movements give you much more control. Now we’re ready to start painting!

Before you begin, make sure your air hose is securely connected between your airbrush and compressor. Turn on your spray booth or extractor fan. Put on the appropriate mask or respirator for the type of paint you’re using and make sure it properly covers your nose and mouth. Gloves and eye protection should also be worn.

Now prepare your paint. Some paints settle while they sit, so they may need to be mixed before use. Shake or stir the paint according to the manufacturer’s instructions until the colour and consistency are uniform. If you’re using paint from a dropper bottle, shake it thoroughly. For paint in a glass jar or similar container, you may want to stir it using a suitable mixing stick.

When you’re starting out, there’s no reason to fill your entire colour cup. Use a small amount. Add just enough paint to comfortably cover the area you’re working on. From there, add the appropriate thinner.

As we discussed in Episode 2, a general starting point for many water-soluble acrylic paints is roughly two parts paint to one part thinner, while lacquer paints may be closer to one part paint to one part thinner.

These are only starting points. Different brands, colours and environmental conditions can change how much thinner you need. What matters is how the paint sprays!

You can mix your paint and thinner directly inside the colour cup using the backflow technique we learned in Episode 2. Cover the front of the airbrush with your gloved finger or silicone cap, press down for air, and gently pull the trigger backwards. The air will bubble backwards through the colour cup and mix your paint and thinner together. Do this for a few seconds until the mixture is uniform.

If you’re making a custom colour or preparing a larger quantity of paint, I recommend mixing it in a separate bottle first. That way you can keep the colour consistent throughout the entire project without having to mix it again from scratch.

When paint hits the surface of your model, you want it to settle into a smooth, even layer. The surface may look slightly wet when the paint first lands, but it should not become soaked. If you notice a large glossy puddle beginning to form, you’re applying too much paint, so move on to another section and give that area time to dry.

One of the biggest beginner mistakes is trying to make the first coat completely opaque. You don’t need to. It’s usually better to apply multiple thin coats and gradually build the colour. Your first pass may look slightly transparent. Let the paint settle, then come back with another pass.

Building colour slowly gives the paint a chance to stick in an even layer and greatly reduces the chances of pooling, running or obscuring surface detail. Remember to watch the surface of your model for these signs.

Try not to hold the airbrush in one place while spraying. Keep your hand moving smoothly across the surface. Begin your movement, introduce paint, continue across the model, then stop the paint after stopping your hand.

This creates much cleaner and more consistent coverage. You should also try to keep the airbrush at a reasonably consistent distance from the model. Moving closer creates a smaller, more concentrated spray pattern, but also introduces paint at a higher velocity. Moving farther away gives you a wider, softer pattern. You’ll use both approaches eventually, but for basic coverage, consistency is more important than precision.

At this point, you know how to set up your airbrush, prepare your paint and actually start spraying. There’s one more skill you absolutely need before you begin painting regularly: Cleaning your airbrush!

It’s important that you watch Episode 4 and understand the cleaning process before starting your first proper painting session.

Cleaning your airbrush properly will prevent the majority of common problems beginners experience and keep your equipment working reliably.

In Episode 4, we’ll go through routine cleaning, deeper cleaning, clogs, dried paint and basic troubleshooting. Once you’ve watched that, you’ll have everything you need to start airbrushing.

Until then, happy building!

— Liam's Hobby Room × BC Hobbies