From the Blog
Tips for Buying an Airbrush
The most important thing to remember when buying an airbrush for model kit building is that all airbrushes are not created to handle paint. An illustrator’s airbrush, with its extremely fine tips and nozzles, is designed for inks, and clog if acrylic or enamel paints are used in it. Avoid this choice. Happily, since the modeller’s airbrushes are also more economical, this first wise choice thereby ensures saving a good amount of money.
Some modellers use a single airbrush; some have several, each of which has its preferred uses. Whether selecting an additional airbrush or a first airbrush, issues to be considered include whether the brush has single- or double-action; a gravity or siphon feed; an internal or external mix; and what size nozzle and needle combination is required. Modellers’ airbrushes are available online and may be bought singly or in kits that include the required compressor and all necessary attachments.
Key Considerations in Selecting an Airbrush
Modellers selecting airbrushes look first at how the airbrush handles. This includes several issues related to how the airbrush is controlled, how paint feeds into and out of the airbrush, and what size nozzle and needle combination provides the best outcome for the desired product.
Single-Action or Double-Action
The first decision in selection of an airbrush is whether it is a single-action or double-action airbrush. The action of an airbrush refers to how airflow and paint volume are controlled.
The trigger in a single-action airbrush controls only the airflow. The paint flow is separately controlled by adjusting the needle depth in the nozzle, which is usually by adjusting a screw at the rear of the airbrush. When a heavier or lighter paint flow is required, the user must stop to adjust the screw. The opposing benefit is that these kinds of airbrushes are easier to learn to use and maintain.
The trigger in a double-action airbrush controls airflow and paint volume. When the trigger is pushed down, it increases the airflow, just as it does in the single-action airbrush. But when the trigger is pulled back, it causes paint to start flowing. The further the trigger is pulled, the more paint flows. This means that when using a double-action airbrush, the paint flow may be continually adjusted. Managing the two actions at the same time takes practise, so the learning curve for a double-action airbrush is a bit longer.
Gravity Feed or Siphon Feed
The next important decision is how the paint is fed into the airbrush. A gravity feed airbrush has a paint cup at the top or side that holds the paint. Gravity draws the paint downward into the atomizing chamber. A siphon feed airbrush has a bottle or other container below the airbrush, connected by a tube to the mixing chamber. As air blows across the top of the tube, it draws paint up the tube, as up a siphon, into the chamber to be atomized and sprayed.
Gravity feed airbrushes require lower air pressures but also hold smaller amounts of paint. The lower air pressures can be an advantage when painting fine lines on models because they make it easier to avoid overspray. Siphon feed airbrushes hold larger paint quantities which can be advantageous for painting large models, such as aircraft carriers. Some who work in acrylic paint also prefer a siphon feed because of the speed with which acrylic paint can dry in the gravity feed cup. A cap for the cup is another solution if a gravity feed airbrush is the user’s general preference.
There is no right or wrong cup size. Options vary from 0.9 ml to 15 ml, with bottles for siphon fed models somewhat larger. The best size for a modeller is the size he or she is comfortable working with.
Internal or External Mix
The “mix” in an airbrush refers to the location where paint and air are mixed and atomized for spraying. In an internal mix airbrush, the paint is atomized inside the airbrush. External mix airbrushes usually do not have any paint enter the body of the airbrush. Paint flowing along the outside of the airbrush is atomized when it hits the airstream near the nozzle. The finish produced by internal mix airbrushes is usually finer and smoother, making these brushes the usual choice of modellers.
The Right Size Nozzle and Needle
First things first: A tiny needle and nozzle does not guarantee a fine line. In fact, using acrylic or enamel paints in the tiny needles and nozzles designed for illustrators’ ink is guaranteed to clog the fine tips. An airbrush’s needle and tips are much like the nozzles of a garden hose. Even a short squat one that is designed to deliver spray over a wide region has a small area near the tip where a rushing narrow spray appears. A long nozzle delivers a generally narrower spray even much further from the tip.
The right nozzle and needle combination for a particular modeller is something that emerges over time as he or she practices with the airbrush and learns how to use it. One modeller’s preference to work extremely close leads to a particular choice; another modeller who prefers to work farther back ends up making a different choice. Neither choice is incorrect as long as it produces the results the modeller desires.
Airbrush Models to Consider
With many airbrush models on the market, several are referenced multiple times by military model painters. They include those in the table below.
Cup Size (ml)
Nozzle Sizes; Pattern Detail (mm)
|Aztek, associated with Testor paints||2.5 – 12; also siphon bottles||0.3 – 0.7; NA||Single or dual offered; users report that proper daily flow requires soaking removable tips in thinner overnight||£ – ££|
|Badger 200-5||NA- siphon fed||NA||Single action; siphon feed||£|
|Harder & Steenbeck Evolution Two In One||2 and 5||0.2 and 04; NA||Dual action; users recommend it for military model painting||££|
|Iwata Revolution CR||9||0.5; 0.5 – 38||Dual-action, internal mix, gravity fed, may be used with solvent-based paints||££|
|Neo for Iwata Gravity Fed Airbrush||9 and 1.8||0.35; fine to medium detail||Dual-action, internal mix, gravity fed; air pressure between 5 and 35 psi||£|
|Paasche H||NR -siphon fed||NA; 0.8 – 25||Single action; external mix; some models have thicker handles, which may be a plus for some modellers||££|
If enamel paints are to be used, make sure that every part of the airbrush purchased can stand up to the solvent used to clean it. The incredible dissolving airbrush is one magic trick no modeller wants to practice.
An airbrush, by itself, is not sufficient to get painting. Some of the other essential parts of the typical airbrush kit include the following:
- Moisture trap
- Airbrush cleaner
- Airbrush cleaning brushes
- Fittings and connectors
Compressed Air Supply
Every airbrush requires a source of compressed air to run. Many modellers use a small compressor purchased at a hobby shop specifically for use with an airbrush. Some adapt a larger compressor designed for industrial use, which can be more cost effective but is generally noisier. For a virtually silent solution, others lease a tank of compressed air from a beverage or welding distributor. These tanks actually contain carbon dioxide or nitrogen, and are virtually silent during operation. They need replacement at least annually and more typically several times a year, depending on the frequency of use.
Many modellers have difficulties related to pulsing in the compressor tank, causing an irregular paint flow. Smaller tanks can reduce this problem. Compressor vendors often can offer suggestions as well. Another compressor issue to be addressed is the accumulation of moisture in the hose line from the compressor to the air gun. Amoisture trap takes care of this.
Buying an Airbrush online for Model Kit Building
A wide selection of airbrushes is offered online for those who build model kits of every kind. Your keyword search for “airbrush” may also bring up such items asairbrush paint and airbrush stencils. To eliminate these from your search for convenience, use the Advanced Search feature and note the words “paint” and “stencils” as words to eliminate from the search.
Other Items to Consider
When purchasing an airbrush for model painting a few other items that may be considered are a spray booth and respirators, to keep the operator safe from paint fumes; mixing bottles or cups to produce exactly the right colours; and an airbrush cleaner or an airbrush cleaning kit . An economical way to buy an airbrush is often as part of an airbrush kit, which includes the compressor and hoses required to run the airbrush. Be aware that the relatively low-priced compressors included in most of these kits may not as quiet as other options available.
The modelling hobbyist who needs an airbrush, whether the first or an additional one, has a wide range of options to consider. Whether painting a fighter aircraft at 1:16 or an aircraft carrier at 1:350, the modeller is looking for an airbrush that allows for smooth, accurate rendering of the designs. Single-action airbrushes are relatively quick to learn, but double-action models allow for paint flow adjustment “on the fly”. Siphon feed models allow for larger volumes of paint to be maintained without removal to a special container. Gravity feed models are less bulky. Needle and nozzle sizes must be large enough to allow the desired kind of paint to pass while permitting the desired level of detail to be created.
Many brands of airbrush are well-known and liked among model kit builders. They are sold singly or in kits along with the nozzles, needles, compressors, hoses, and connectors necessary for their functioning. Whether purchased alone or in a kit, a quality airbrush appropriate to the modeller’s needs is easy to find online.