Over at Gailbraithe's Black Primer Paint blog.
Follow the posts backwards to get the full log of the build.
I've been tempted in the past to at least think about a scrapyard terrain set for A&A but never got around to it. Mainly because it struck me as taking a lot of painting so I Like Gailbraithe's approach of lots of red oxide primer. It looks nice and stylised and nicely frames his models. Good stuff. I may take his ideas over to my 40k Combat Patrol collection.