If you want to paint an old, rusted vehicle or metal siding for your diorama, you might want to try the hairspray technique. Basically, you paint a base color, spray it with hairspray, and then paint the object with another color. Once the paint has dried, you use water and a short-bristled brush to remove some of the top layer of paint, revealing the base color. The results can be very satisfying, as you will see in this video.
Painting old and distressed vehicles can be a lot of fun. There are a variety of techniques to achieve a weather-beaten look, but have you ever used kitchen salt in your painting? Once you watch this video, you will definitely want to add a dash of salt to your painting toolkit.