I store my barrel blanks and used barrels differently. I hose them down inside and out with LPS-3. I then wrap then in plastic wrap, like from the kitchen. Sealed up tight with many layers, burrito style. I put a card in the wrap describing the barrel. They are then stored in a cabinet in a big pile. My location has very low humidity. The platic wrap helps prevent scratches. I have to many barrels for pegs on a wall and don't have space to store them vertiically. Never seen a spec of rust on any of them.