Hello Michael Palmer et al, as you have experience with Masonite and I don't, I wonder if that material choice is not a bit suspect. For one thing, Masonite is quickly affected by moisture, for another, I also suspect that in the Masonite production there are some pretty nasty chemicals being used and I would not use it near our bees. I would stick to pine and interior plywood with good coatings such as bees wax or what I have used in the past, Fiberglass resin with a long aeration period. However, I am always open to learning something new, thanks. Take care and have fun