Dylan's Woodworking Blog: Steam-Bending Shaker Oval Boxes

Oval boxes were some of the best known items produced by the Shaker community from the late 1700s - mid 20th century. They were used to hold everything from flour in the food pantry to nails in the workroom, were as small as 2" in length to as large as over a foot, and were used throughout the Shaker communities as well as sold to the general public.

To make the iconic oval shape of the box, I experimented with the technique of steam bending solid wood.

Historical Perspective

Historically, Shaker oval boxes changed little in structure until after 1870, when they began to be finished in a variety of different colors and patterns using milk paints. In the 2nd quarter of the 20th century, many Shaker communities added handles and lined the boxes with bright materials, such as patterned cloth or silk. These kinds of boxes were not too difficult to produce, and were very popular sale items amongst tourists visiting Shaker communities.

Collage of Shaker Boxes I Assembled From Photos in 'The Shaker World' by John T. Kirk

Preparing the Strips to Bend

The first step of making a Shaker oval box is to prepare 2 thin strips of wood (one for the body and one for the lid) which are then steamed, bent into an overlapping oval shape, and held together with copper tacks.

On one end, a unique pattern (called the swallowtails) is cut with a knife which allows for the wood to expand and contract without splitting during temperature & humidity changes. Historically, these were cut in a gothic arch pattern, but I decided to round mine out more, since I prefer that look.

At the other end, the wood is thinned using a hand plane or sand paper so that the overlapping seam inside the box is more subtle. The final step before bending is to layout and pre-drill pilot holes for the copper tacks.

The Science Behind Steam Bending

Steam bending is the process by which we introduce enough heat and moisture into a piece of solid wood to make it flexible enough to bend without breaking - a process known as 'plasticizing' the wood. During this process, the wood's lignin (the 'glue' that holds the wood fibers together) is softened enough so that wood fibers are pliable. Once the wood dries and cools down, it will largely retain its bent shape without a loss of strength in the wood fibers.

(Left) Lignin - Diagram
(Right) Steam Box Used to Plasticize Wood - Diagram

Steaming the Strips

Steam Bending the Wood

I let the strips sit in the steam box for about 20 minutes before taking it out to bend (wood is typically steamed for about ~1hr per 1" of thickness).

After taking out the strip used for the box's main body, I wrapped it around a bending form I made and taped it to hold shape. Then, I took out the lid strip, wrapped it around the body, and taped it as well.

Next, I slipped both the taped lid and body off the bending form and put 2 ovals with finger holes on either opening of the box. I made these thinner ovals to help the box hold shape when drying and cooling down, without having to leave it on the bending form (so that my group mates could use it after me).

(Left) Bending Form & Ovals
(Right) Taped Box After Bending

Tacking the Box

Hammering the Copper Tacks

After letting the wood sit overnight, I removed the tape and made a marking where the ends of the swallowtails overlapped the box sides. Even though the wood has been bent into the oval shape, it still springs back quite a bit, so copper tacks are needed to help it hold shape.

By placing the strips onto a pipe, I hammered in the copper tacks into the pilot holes. When the tacks hit the pipe below, they cinch and flip over, which secures the 2 parts of the overlapping strip.

Securing the Lid

To make the lid for the box, I traced the bottom of the box's main body and the top of the lid strip onto a 1/4" piece of solid wood, which I then bandsawed and sanded to fit the inner circumference of the strips.

To secure the top & bottom to the box, I went the historical way of drilling holes around the box perimeter that I fill with toothpicks to hold the lid & bottom pieces secure.