The Art of Steam Bending

It can be a beguiling and magical experience to witness solid timber being manipulated and curved into various forms. This is why we like to offer steam bending as one of the main components in the woodworking courses we offer at Edward Johnson’s School of Craft.

What is steam bending?

Steam bending is a traditional technique that was once widely used in the production of weapons, tools and vessels. It is now still used in the manufacture of furniture, crafting of musical instruments such as violins, and in boatbuilding. It is an effective way to shape timber to add beautiful twists, bends and turns to your designs and projects.

A series of small images showing various stages of steam bending in the workshop — Steam bending timber in the workshop to make components for the Sussex Chair

How do you steam bend wood?

The method is to expose the timber to steam to make it pliable. The heat and moisture from the steam gradually soften the timber’s fibres enough for it to be bent when still warm and retain the shape once it has cooled.

The timber is placed in a steam box for a set amount of time depending on the thickness and type of wood. Sometimes the timing needs to be calculated by trial and error to get it exactly right, however, the general rule of thumb is to allow one hour per inch of timber thickness. Once the timber is ready it gets manually pulled around a former or jig as quickly as possible.

In the photo below you can see how we use a reinforcing metal band to the outside of the timber to prevent ‘blowout’. In other words, to prevent it from splitting. The metal band helps to support the strained timber that is put under compression and tension. Inevitably you will get splits due to timbers’ natural and individual characteristics. However, this additional support helps considerably to minimise this problem. Once in the desired form the timber is then clamped into position and then left to cool and dry.

Three cabinet makers steam bending wood in a jig — Using a reinforcing metal band on the outside of the timber during the steam bending process

Is steam bending the only way to curve and shape timber?

No, certainly not. Steam bending is one effective way, and it can get fantastic results. However, another traditional tried and tested way is to laminate timber to create curves and bends. It really does depend on what you are trying to achieve and then choosing the most suitable application for your design.

Do you use steam bending to make your furniture?

For those who are familiar with Edward Johnson’s work will know that, more often than not, it involves many curved elements. We frequently get asked if we steam bend our timber, especially with regards to his Freeform technique and design style. The answer to this question is yes, on occasion we do, although it is important to note that we use more than one technique to make our curved furniture.

As touched on above, another construction technique we use frequently to make our curved elements is the process of laminating which is one of Ed’s specialities. Laminating involves gluing together many thin strips of timber, which you then bend and manipulate into position around a jig. It is then clamped tight, and once dry it is shaped and refined, in our case, usually by hand with a traditional spoke shave.

However, there are circumstances when we do use steam bending to produce certain results. It all comes down to each design, and what technique would best suit what we are wanting to achieve.

Two good examples from our portfolio that incorporate steam bending are our Sussex Mirror (for which we offer a course) and our Sussex Chair which both form part of Edward’s Sussex Collection.

Sussex Mirror
Sussex Chair

Steam bending versus laminating

There are both benefits and disadvantages to using steam bending over the laminating process. Steam bending can be a lot quicker once you have worked out the timings. There is far less material waste, no need to wait for glue to dry, and tighter curves can be achieved. However, on the downside it can take a lot of strength to bend it depending on size. You need to work the timber very quickly, and sometimes the timber is prone to splitting and blowout when bent or removed from the mould. It is good to note that some species of timber are also more suitable than others. For the purposes of steam bending, we tend to use oak and ash for this process (although others can be used of course). It is advisable to choose timbers that have a straight grain wherever possible, and knots are best avoided!

Like most things, when choosing which technique to use it is all about having the knowledge and experience to be able to achieve the desired outcome with the best results.