Steam Bending

Steam Bending:

Most woods can be steam bent. Steam bending is a rather simple process that is exactly what it sounds like, bending wood with steam. Some of the best woods to bend are blackberry, white oak, red oak, magnolia, walnut, pecan, hickory, beech, elm, and birch. Soft woods do not tend to bend as well.

It works by re-adding moisture to the fibres in the wood, this allows them to bend and flex, and therefore they can be moulded. Moisture is added by putting the wood in a rack in a cylinder filled with steam from a pump. There is a general rule of thumb with steam bending, and that is for every inch of wood equals one hour in the steam being cured. So if a piece of wood is five inches thick then it requires five hours in the steam before attempting to bend. After the wood has been cured for the adequate amount of time the wood is removed from the steamer and is clamped around a mould. The moisture is then sucked back out of the wood; this is done through kiln drying. The drying “locks” the fibres in their position bent around the mould. This means the wood retains its bent shape.

The dangers of steam bending are that if the wood is bent before properly cured then it could be at risk of breaking. It also needs to be bent with the grain; if bent against the grain or the wood contains knots then it could also break whilst bending.

The process is used on a small scale making jewellery and one off furniture. But traditionally it was used on a larger scale to form the primary structure for hulls of boats.