Just as with a real demonstration of weathering where it is not possible to use an airbrush, the next part of this demonstration doesn’t lend itself to the medium on which it is being delivered.
What follows is a picture of my airbrush with the “small” cup fitted; the standard “large” cup is shown above the control valve so that you can see the difference. In case anyone is wondering, the rather complicated gubbins on the bottom is a quick release mechanism which allows me to remove the brush from the air hose quickly for cleaning or changing brushes.
When I prepare my airbrush for weathering I fit up the smallest cup I can muster and with a pipette I roughly half fill it with thinners – in my case preferring to use enamel paints that will be white spirit. I then dip a good sized brush into a bottle of my chosen paint and dip it into the cup of the airbrush and work a smallish amount into the thinner. This gives a mixture that is stronger in consistency than a wash but thinner than the traditional 50/50 paint/thinner mixture that you hear talked about by people who properly paint models with an airbrush.
The first colour to use is Railmatch Frame Dirt. A quick spray onto a piece of plain white paper will allow you to see the effect you will be adding to the model. If it is too dense dilute it with more white spirit, if it is too dark a little lighter paint could be added although Frame Dirt is a really good colour choice for this job.
The photos of models I am using for these notes were largely taken when I was on the masterclass run by Mick Bonwick at the Missenden Abbey Modellers weekend.
The first image is of a pristine BR standard unfitted 20T Brake Van.
The next photo shows it after it has had its planking emphasised with dark wash, had the blobs cleaned up and then a light spray with Railmatch Frame Dirt.
In this picture the roof has also been airbrushed, but this time the paint mix has had a little Railmatch Roof Dirt added to the Frame Dirt. Roof Dirt is actually a very dark colour and some people consider it to be “too modern” for the steam era. My personal view is that applied sparingly it does actually represent the sort of colour that was seen on carriage and van roofs.
In the background of this photo you will also see the BG from the previous notes on washes. This has also now had a light-ish airbrushing with Frame Dirt below the solebars with a little bleed-up into the lower body. The next stage for this model will be to have the roof and upper body airbrushed. If you check back to the previous notes you will see that the “blobs” caused by the application of the enamel wash have been effectively removed leaving the door recesses and hinges nicely highlighted.