I dunno. My DH & I just made a homemade chicken feeder for our "tractor" out of scrap plywood that was left. I was wondering about painting the inside of the feeder with water-based polyurethane so the oils from the feed don't permeate the wood. Yes? No? Hubby said to check with those who know. The feeder will be mounted on the wall inside the coop. Thanks for any advice.