My recent production of Windsor chairs prompted a reader – himself, a Windsor chair-maker – to contact me concerning the moisture content of various chair parts.
We exchanged several emails, the content of which I have précised and edited together with a couple of similar emails from other chair-makers into the following dialogue.
Chairbler: I made a small kiln with a light globe in it. I put the ends of my turned legs and stretchers in there overnight to really bring the moisture down before I turn my tenons. What method do you use to dry your tenons?
JP: I don’t go to such lengths to dry them: In the damper months, I may leave partially-turned legs and stretchers in the shop for a while before completing the tenons.
Chairbler: It’s essential to have dry tenons to avoid your joints working loose. I dry all my tenons and haven’t had a single failure. Do you use kiln dried lumber for your chairs?
JP: Obviously sound joints are a prerequisite of any furniture. I use air-dried wood for the chairs I make and bring it into the shop as and when required. I haven’t experienced any chairs falling apart either.
Out of interest, does it require much effort to assemble one of your chairs?
Chairbler: After I have dried my legs and stretchers I accurately turn my tenons so they are a snug fit. This makes the chairs easy to assemble and when the tenons get back to equilibrium they swell and tighten.
JP: With only a “snug fit” during assembly, are you concerned at all about any effects that might arise from the mortises becoming ovoid as they dry out? Do you artificially dry seats and crest rails too prior to boring the mortises in them?
Chairbler: I don’t think it’s necessary and I haven’t tried it. I am amazed you get good joints using air dried lumber.
JP: All my learning is based on observation of traditional methods. The majority of eighteenth- and nineteenth-century Windsor chairs were made from – at best – air-dried wood and many were made using green wood (or something between green and air-dried). I too turn tenons fairly precisely however, I turn them to be a pretty tight fit which require a big hammer to assemble (as does all the other joinery and dovetailing I produce – I’m not fond of “snug”).
Fig. 1. A big hammer being employed to knock stretchers into legs.
Fig. 2. Thumping an undercarriage into a seat.
During examination of period Windsor chair joints, this method is evident where the rough-turned tenons have dragged the fibres in the mortise sides in the direction of entry and which are locked for perpetuity by the glue.
The survival of many thousands of eighteenth- and nineteenth-century Windsor chairs endorses the efficacy of this simple technology.
Jack Plane
Glue?
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Do I use it? Yes. Type? Animal.
JP
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My big hammer has served me well is such endeavors.
Good article Jack.
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As luck would have it I just finished a ladder back chair course with Drew Langsner. We used a “middle way” approach (my quote marks): legs air dried, rungs made slightly drier than legs with an overnight visit to a box heated to about 100 F., tenons then formed tight enough to require the big hammer to assemble, and with the “ray plane” (quartered aspect) vertical to best accommodate the mortises becoming ovoid as they dry. Mr. Langsner, questioned about the temperature of the kiln and drying time, suggested it’s easy to over-think and over-do the difference in moisture between legs and rungs.
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When I did my chair making course in Australia, we dried the tenons overnight in hot sand. I use this method in my workshop on polelathe greenwood turned legs and use a snug fit with hide glueing and wedges glue and hammered home with a wooden mallet. This method has worked for the last 10 or so years without problems.
Are you polelathe turning Jack?
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I made myself a pole lathe in my teens, but quickly tired of it and bought a cheap, nasty powered lathe as soon as funds permitted.
I have power in the shed and nowadays am more about the destination than the journey.
JP
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