Here it is - after two days of baking in the sun, then an overnight drying in the hot water heater room, I've neutralized, rinsed, and ironed my first piece of rusted fabric. It started out as a half yard of bleached PFD Dyers' Cloth. I followed instructions posted on QuiltArt List, and they worked like a charm! The colour is great - more orange than I expected, but looks really neat, with the darkest areas where it was touching the rusted metal, and lighter areas evening out (I kept it good and soaked while it baked in the sun). This is a fabric alteration technique I will definately be doing again. Now I just need to find more rusty things to play with.