I have a Summerhawk Ranch coop for an extra coop for birds I want to keep separate. I have just cleaned it thoroughly in prep for moving my chicks into it. The metal tray that slides in to catch poo is rusted. We have removed what rust we can with sanding and rust remover, and we'd like to seal it and/or do something to keep it from rusting again and also to provide a barrier so if the chicks scratch at it, they won't be getting rust. I have a spray urethane product. I know there are rustoleum spray products out there also, that are made for this. I just want to investigate the safety of using those products for this purpose. We are also wondering if we should just take that metal piece out and replace it, but would rather not! It will be mostly covered with pellets or shavings, but you know how they scratch around! Any advice would be appreciated!