Steam Bending and Wood Moisture Content

Wood needs an MC of 16% or higher to be steam bent. August 21, 2006

Question
In the Architectural forum there is a comment that you can not successfully steam bend kiln dried wood. Is this fact? If so what is the preferred MC for wood that is slated to be steam bent - let's say, in a production setting of chair making?

Forum Responses
(Sawing and Drying Forum)
From Gene Wengert, technical advisor, Sawing and Drying Forum:
That is basically a true statement indeed. The preferred MC so that you will not get breakage is 16% for mild bends and 23-25% MC for severe bends. Of course, steaming and end pressure are also important, as well as grain angle and grain direction.



From the original questioner:
Thank you Doc for the reply! So after steaming and with this high MC for a rear chair leg, are they then put in clamps and pushed into a kiln? What's the routine for getting the final drying? Again, I am thinking in a production setting.


From Gene Wengert, technical advisor, Sawing and Drying Forum:
One popular approach is to put the pieces into a hot room (90 F or 100 F) while still in the clamps. Drying may take a week, give or take.