Making Curved Chair Arms

Ideas for fabricating a curved wooden sofa arm. September 18, 2014

Question (WOODWEB Member) :
We have received a commission to build a walnut sofa that is to incorporate the curved arms similar to the photo below. My first thought is to do a bent lamination assembly. I had considered doing steam bending but two concerns made me re-think that method. Number one a tight radius at the rear of the arm using walnut and number two maintaining accurate dimensions between the arms so they can be integrated with sofa frame. Another question is how to best get the tapered shape of the tops of the arm. I could imagine the easiest way is to template rout the flat stock and then steam bend. So it may be a compelling reason to reconsider steam bending.

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Forum Responses
(Furniture Making Forum)
From Contributor M:
Not sure what you or your customers specifications are but are you sure the arms in the image are a single piece? The image quality is not great but zooming in it looks as though there may be a joint in the left arm. If that were the case one could guess the arms in the image may be four piece/segmented? This is all moot if you or your client insists on one piece arms.

From the original questioner:
It was my thought as welI thinking that the break would be at the lower part of the notch on the arm. I have a few other photos and as much as I try I can't convince myself that there is any break anywhere.

From Contributor H:
When doing work like tapering pre-bent parts we will take a piece of bending ply and cut it to shape. Then we'll wrap it around the curved piece and either flush cut with a router bit and template guide or bearing, or trace and band saw to shape. It is easy to cut the bending ply to shape while it is laid out flat.

From the original questioner:
Are you suggesting bending the material and then template routing after glue up? I had thought of that but my concern was that the back section of the arm is only 2 wide with a 4 radius and that it would be difficult to keep a laminate trimmer balanced and square to the cut. The more I think about it, it does seem to be the way to do it.

From Contributor C:
Tapered bent lamination! Its simple, repeatable and far stronger that piecing four parts together. The bending form can even be used to shape the arm once the glue is cured. Don't use yellow or white glue as it will allow some creep and the glue lines will tend to stand proud of the wood after some time. I use a two-part U/F glue or hide glue and with walnut you will be very hard pressed to tell that the arm is laminated and you will have an even harder time identifying the glue lines.