I'm in the process of building a treadle feeder for my girls, made from 12mm plywood, and wondering what to seal/paint it with that's both weatherproof (or at least, will seal the wood ends against moisture getting in) and also chicken friendly in case they peck at it. Any ideas?
I used an exterior grade polyurethane for mine. I'm not completely satisfied with it. In the very worst of our rain storms the treadle assembly can swell and keep the lid from closing until the air dries out. I'm not sure if this a problem or not where humidity levels are generally higher. Maybe if I put another coat or two on it that might not happen. It only affects the feeder one or two days a year, but it's a bit annoying. I should note that the feed inside never gets wet. I ended up building a little shelter that covers one of the treadle feeders and it works pretty well keeping out the rain in it's current location.
The BEST way would be keep it indoors. Spar Varnish would be a good finish, but if it's exposed to the weather you will still have problems
Unfortunately indoors isn't an option until I build my next coop, but I like the idea of riggin gup a shelter for it somehow. Gallo del Cielo - your one is actually what gave me the inspiration!