How would you go about bending stair rails in order to get something like what is pictured below?
I'm asking out of curiosity, not because I plan to try this myself. My house, built circa 1900, has rails similar to this, as well as some other fancy curved woodwork, and I'm wondering how they made the wood curvy. The only information I can find about bending wood involves doing it with laminate strips and glue, but there is no sign that my house's woodwork was done that way.
They use a steam box and pre shaped forms. The wood is inserted into the box and sealed. Then steam is applied to one end of the box and allowed to escape from the other end. After removing, the lumber is worked around the form and clamped. Once set the finishing and shaping can start. It's a very old technique and saw large scale use in shipbuilding. I've seen guys do it in the field with a small steam box. It's pretty easy to work with. Some woods are better suited than others.
In the specific image you shared, it appears that the rail is made from multiple short pieces glued end to end. It looks like each piece is machined to be slightly curved, and due to the oval nature of the stairs, each is probably cut with a slightly different angle.
