Just before the game the other night I had a bit of time to finish off the storage tank for my manufactorum. After it was painted to look dirty I gave the velding lines a brownish wash added some dark brown spots and painted metal bits rusted. Then using a Vallejo rust wash added stripes of rust running down the sides, emphasized the brown spots and underside of the velding lines. The I added some vallejo liquid mask and painted the omega logo in that area. After the red paint was dry I carefully removed the mask with a finger and it yielded a pretty cool chipped appearance.