In response to S’s question a while back, I’m doing a few posts on the tools used in heritage coopering.
Many of these tools are still used in modern cooperages, though the process is more mechanized. We’ll look at tools in the general order in which they were used. First, the cooper would select a length of tree trunk (usually oak) and quarter and square it in preparation to cut staves. Then, using a Froe, the cooper would split staves.
There are references to cooper’s froes that are curved, but we have a straight froe in our cooperage. Once split, the ends of the staves were tapered off with an axe. The stave was then set into a shaving horse to hold the work tight.
The outside of the stave was then rounded with a ‘Backing Knife’.
Once the cooper had the outside of the stave properly shaped, the inside of the stave was hollowed with a ‘Hollow Knife’ to achieve a uniform thickness. The edges of the stave are then planed to the correct angle so the staves will fit snugly together. The shape of the beer cask is
important. The bulge (which is more pronounced in beer casks than in casks built to hold wine or spirits) is the casks source of strength. When the staves are locked in place by the iron hoops, they act like the stones of an archway, each exerting equal pressure on the next to strengthen the whole. The next post will be on the tools used to assemble the staves and hoop them together.