How do we choose which airbrush is right for you and your planned project?
Before we can make an informed choice I will explain the types of brushes, and how they work by showing both types of airbrushes in there component parts.
There are two types of brush, the first is a single action external mix and the second is dual action internal mix.
The external mix brush is as it indicates, the air and paint are mixed at the front of the nozzle. This type of brush is great for covering large areas, but can be limiting for fine detailing work as you have reduced control over the paint and air mixture, due to these brushes using a single control. By depressing the top button it releases more air and in turn causes more paint to be mixed into the airflow, giving a greater coverage (I will cover the control of the paint mixture in the next tutorial).
The internal mix brush is the most controllable of the two types, and will allow you to paint finer detail. As most of these brushes have a two stage control over both the air pressure and paint flow, combined with the internal mix means that finer lines can be achieved. The air is controlled by depressing the button and the paint by pulling the same button backwards, thus increasing the paint flow.
This type of brush is my preferred one, regardless of the type of model I may be making. When covering the a larger area you may need to allow more time to spray, as the jet of spray is finer so more layers / passes maybe required. This type of brush performs extremely well when undertaking fine detail such as weathering and panel lines on aircraft (I will be covering this in another tutorial).
This first image shows the basic components of the external mix brush, as you can see the paint outlet which fits inside the nozzle.
The air pressure builds up as you depress the trigger it causes more paint to be sucked up into the nozzle, and to be mixed into the jet of air giving the spray.
The image of the internal mix brush show the nozzle off the brush exposing the needle tip, and I have removed the rear cover showing the needle grip nut.
With this model when you depress the trigger straight down it causes the air to travel through the chamber to the nozzle. When you combine the depressed trigger with a backward action it will start to let the paint be sucked or gravity fed into the air flow. This is then mixed in the chamber with the air and comes out of the nozzle as the spray jet, and depending on the amount of backward movement on the trigger will increase the paints density (I will cover the control of the paint mixture in the next tutorial).
Now we have a basic understanding of the operation and types of airbrush available, we need to think about the types and amount of modelling you plan to do as this will determine which brush you plan to purchase.
If you plan to only do a little bit of spray work then maybe a single stage external mix could be the one, however if like me you do a lot of work then a high quality internal mix with two stage control is the option for you.
I will be covering the operation of the airbrush in the next tutorial which will discuss the use of air canisters, compressors and paint mixtures.
Which ever brush you purchase there is one item that you will need even before you open the box, and that is a very good mask to cover your mouth and nose. The particles from the spray will cause breathing problems, regardless of the paint type you plan to use. Also think about those around you, including your pets, and where possible find a well ventilated area to work that is away from your loved ones.
I recommend speaking to your local builders merchants or hardware store for advise on the mask type that is best for the job. DON'T skimp on this piece of kit as it could save you from having health issue later on!
As always, if you have any questions about weathering & detailing models for your layout, please feel free to email them to me and I will be pleased to assist you.