The Craft of Coopering
Staves and a hoop make a watertight vessel
Synopsis: Carl Swensson’s staved vessels are inspired by traditional Swiss milking buckets. This coopered version with an interlocking hoop was a real challenge. Here, Swensson unlocks the secrets to his design and technique for building it.
Carl Swensson’s staved vessels (Back Cover) are inspired by the traditional milking buckets of Swiss cooper Ruedi Kohler (FWW #40). To make this faceted version, Swensson first makes a tapered, smooth-sided bucket, then disassembles it to continue shaping the staves. Getting the staves just right is a challenge, but Swensson says that making the interlocking hoop (p. 90) is the real hurdle. The secret to successful bending, he found, is pre-limbering: Before cutting the arrow lock joinery, he soaks and steams the hoop blanks, then bends them to a spiral much tighter than the bucket itself. This breaks the lignin bonds in the wood, rendering it almost floppy. After cutting the joinery, Swensson resoaks the hoop and it bends to shape easily.
After cutting the stave to length and planing the outside face convex, Swensson shoots the miters on an inverted try plane. Next, he scoops the inside face with a cooper’s drawknife. Then he drills for a pair of locating pegs in each joint. Working from the bottom of the bucket to the sawkerf, Swensson chisels a flat to receive the hoop. He smooths it with a sanding belt.
Tape on the saw saw acts as a depth gauge. After dry-assembling the staves with a temporary strap, Swensson cuts a kerf around the bucket using a handsaw. After dry-assembling the staves with a temporary strap, Swenson cuts a kerf around the bucket using a bandsaw.
Swensson uses a template to mark the inside profile of each stave. To give the vessel its faceted look, he planes the area above the hoop relief…