I've been looking at cooperage as I will need to make some waterbreakers and buckets shortly.. it's just a math problem to make the staves, divide the large and smaller circumferences by the number staves predicted with these numbers make a pattern,, most coopers have a wall of patterns.. thinking about carving a plug the barrel shape, soaking the staves so the bend, clamping/strapping them around the plug,, after drying remove the plug and assemble the cask/barrel..