The main issues with this chair included improperly fitted and damaged tenons, which negatively affected the chair’s stability. After labeling the chair’s structural components and marking the needed repairs with a piece of tape, we disassembled the chair and prepared full-sized drawings of tenon repairs — the angled tenons are common in tapered chair stretchers. We used three typical tenon repairs:
1) When the tenon damage was extensive, the tenon was sawed off flush with the end of the rail, a new mortise drilled out and chiseled, and a new loose tenon made from hardwood was fashioned to fit snugly into the mortise. An often used alternative to making a loose tenon is to fill the original mortise with a hardwood plug and replace the tenons with dowels — this repair is typically faster, yet yields inferior results due to reduced gluing area, hence we avoid it.
2) When the tenon was sound, it was only expanded to the desired thickness by
a) driving a custom-made hardwood wedge into a sawcut made along the midline of the tenon width, and/or
b) gluing thin pieces of veneer to the face cheeks of the tenon.
Regluing and finishing followed.
