If traps have just a minor surface rust and not deep crusty type then traps are okay to treat right away with boiling dye , cold dip or spray paint. A slight rust will help adhere dye or boiling dye properly. As with natural dyes such as sumac berries , oak, maple bark just brink traps and dye to boil , shut down and let set over nite and traps will be a nice black, brown ect when taken out next day. If going ofter canines , flush traps off with hose to get excess dye off if you are going to wax traps. This is IMPORTANT. All dye is used to help keep trap steel fm rusting ect. On my new canine traps i just boil , rinse, and wax. A canine cant tell a brand new shiny trap under ground lol. When they rust then i treat them in a year or two.. Happy trap fixing