I tried the hairspray technique to make rust on a few 1/35 oil drums I had lying around.
For those of you who don’t know the technique, it is easy:
1- Paint the whole object in orange-brown (rust) color. I did some ‘stippling’ with different shades of brown and orange to get a fake rust ‘texture’.
2- Let it dry thoroughly (overnight in my case).
3- Apply a thin coat of hairspray.
4- Let it dry (15 minutes).
5- Apply a thin top coat with an airbrush. Use acrylic paint.
6- Let it dry (15 minutes).
7- Use a slightly damp brush to wet the surface, one area at a time, and use a tooth pick or a rough brush to rub (gently) against the surface, in strategic spots, to peel the top coat, revealing the rust underneath. The idea is that the water dissolves the hairspray underneath the top coat and makes it easy to create very natural chips and scratches.
8- When done, rinse in water, let dry and apply a matt varnish (Testors Dullcote in my case).