Hi the airbrush is fantastic! My bro was here helping me and did most of the painting and was teaching me along the way, he was an apprentice spray painter so yay! The finish is just as durable as brush painted humbrol acrylic, We have yet to run the tank engine as I want to add a smokebox door and a taller funnel 
For preparation we used wax and grease remover on all surfaces to be painted then tried to avoid touching them as much as possible as to not contaminate the surface. It sure is a bit of messing about with prep and then cleanup compared to brush painting and rattle cans but the results speak for themselves. This morning we repainted 4472 in a slightly lighter shade and think we are close to the decal color, then we clear coated it. Hopefully it will be dry enough to assemble tomorrow. I will show a proper pic of the tank engine when its finished hopefully later today
For preparation we used wax and grease remover on all surfaces to be painted then tried to avoid touching them as much as possible as to not contaminate the surface. It sure is a bit of messing about with prep and then cleanup compared to brush painting and rattle cans but the results speak for themselves. This morning we repainted 4472 in a slightly lighter shade and think we are close to the decal color, then we clear coated it. Hopefully it will be dry enough to assemble tomorrow. I will show a proper pic of the tank engine when its finished hopefully later today