Learning to make Windsor chairs

I like to keep learning about wood as a material, and learning new skills. Learning to make Windsor chairs has been something I have wanted to try, so with the aid of a good book, Youtube, and long distance advice from my friend Barry Horton in France, I have been finding out about Windsor chair construction, making and the reasons behind the choices of timber. I am making a copy of the chair in the picture above.

Windsor chairs are a very clever design. Their construction is fundamentally different when compared with conventional chairs. Different because the seat is the heart of its construction. The legs’ structure is anchored into the underside of the seat into sockets. The back structure is anchored into the top of the seat, also into sockets. The seat, traditionally, is a single piece of elm. Elm is used because its very interlocked grain is resistant to splitting. The turned legs can be beech, ash, oak, it really does not matter. The spindles are of riven (split) ash, because ash is a very flexible wood. Splitting the wood out of the plank is better because the split will follow the grain, and the piece will have greater strength as a result because the grain does not run out. The bent parts are also riven ash, because in addition to its being a flexible timber, it also bends well. It is important, though, for the ash to be air dried, rather than kiln dried. This is because in order to bend the ash it has to be steamed, the heat plasticising the wood. Kilning, however, damages the lignin, not important, unless one wants to bend the wood, and then it is very important that air dried ash is used.

In finding the materials, I found a sawmill in the North York Moors National Park that can supply air dried ash, so a trip ensued, and I selected a 25mm plank with even, straight grain. I split the pieces out that need to be bent. For the elm (which is hard to get these days) I found a small sawmill in Sherwood Forest that had suitably sized planks of wych elm for me to choose from. Happily the elm is air dried too, though for the seat this is not important.

I built a steam box, and made the formers around which to bend the ash, and today, rather nervously, I tried it all. My steam box achieves a temperature of 98 degrees, and 25mm pieces need an hour of steaming. All the preparation paid off, and the ash bent beautifully, I am relieved to say. I will leave the bits to dry now for a while, and get on with other parts of the chair, all the processes for which I have done before.