Adventures in Steam Bending

Video - February 6, 2020

There’s a certain irony surrounding wood bending. Normally, woodworkers do everything they can to mitigate wood movement and prevent boards from bending, cupping and twisting. But sometimes we want a curved project part that simply can’t or shouldn’t be cut from a larger piece. There are two popular methods for bending wood: bent lamination and steam bending. With bent lamination, we saw a board into thin strips and glue the strips back together on a bending form with glue between each layer. This process is fairly predictable and you can do it with any species of wood. I have a video on that process here: Bent Lamination

Steam bending is a very different beast. The process uses steam to transfer heat deep into the wood fibers, causing them to become more pliable for a period of time, long enough for us to clamp the workpiece to a bending form to grant it its new shape. A good analogy is curling hair. With moisture and heat, straight hair can be made curly and curly hair can be made straight. So it is with wood. But because every species is a little bit different, not all species take well to the bending process. Commonly-used species include Ash, Beech, Birch, Hickory, Red Oak, and White Oak. Furthermore, kiln dried wood is significantly more difficult to bend due to the hardening of the lignin imparted by kiln drying.

Since this process was completely new to me I decided to jump in head first, without doing a ton of research, and essentially setting myself up for some failures. But those failures helped me solidify my knowledge on the topic with actual experience and not just taking someone else’s word for it. By the end of this experience, I had read numerous articles, watched tons of videos, and read two books on the topic including one I highly recommend: Wood Bending Made Easy by Lon Schleining. While I’m nowhere near an experienced steam-bender at this point, I do feel I have a much better understanding of what it takes to have repeatable successful steam bends. I also learned that I really prefer the predictability of bent lamination. But having both techniques as arrows in my quiver means I simply have more options when executing future projects.

Here’s a summary of my personal conclusions. Keep in mind that all of these things warrant more testing and research:

  • Soaking doesn’t seem to be necessary for air dried lumber
  • Steam a little longer than the literature recommends
  • Compression straps appear to almost be a necessity. I say almost because I know lots of folks do bending without them.
  • Give the piece plenty of time to dry on the form in a warm area.
  • Kiln Dried just might be more trouble than it’s worth for the occasional steam-bender.

Stuff Shown in the Video: