Having been shown the error of my ways by not fading the van before starting, I shall be embarking on another project where I do fade first. This project was completed as an exercise in using the MIG Dark Wash in all sorts of ways to represent a grimy COV AB.
The roof has been airbrushed with slightly thinned wash, applied as four thin coats and left to dry between each coat. This resulted in a very soft texture that was easily but not completely removed, leaving a slight brownish discolouration to the original factory grey paint.
The first coat of wash on the sides and ends was removed with white spirit and then a fading coat of ComArt Transparent Light Dust was airbrushed all over. This was left to dry and then another couple of thin coats of Dark Wash were applied, as before.
Immediately after application of the wash, a 1/2" flat shader was used to drag the wash downwards from the top to the bottom of all sides and ends. This created a build-up of grime on the top edge of all horizontal surfaces.
A rigger brush was then used to apply the aforementioned wash to all of the rivetted areas and left to capillary action to spread randomly about. Drying was accelerated with the airflow from an airbrush and the whole thing left to dry for several days.
All of the processes mentioned herein will be repeated one step at a time for another vehicle, coming to your screens soon.