Whose cottage doesn’t have a vintage chair with wobbly joints? Let’s look at a simple strategy for restoring structural stability. Until the mid-20th century, animal-based glue was widely used for woodworking. Unfortunately, it breaks down over time, becoming powdery and losing grip. With the advent of synthetic glues, this is no longer a problem; now it’s just poor construction and abuse that weakens chairs.
To fix a rickety chair, assess which components are loose by gripping the chair sides and twisting it to and fro. You can also pull on each part to see what’s loose. If a joint is loose but won’t separate by hand, try tapping it apart with a soft mallet. It’s okay if some of the joints only partially separate.
Apply carpenter’s glue to dowels or spindle ends with a small brush and in holes with a cotton swab, making sure to coat just the surface and not fill the hole. For joints that only partially separate or those that can’t be taken apart, Lee Valley sells Chair Doctor, a low-viscosity glue you apply with a syringe. It will wick into the joint, swelling the wood and conferring structural integrity.
For joints that you can separate, wash off any animal-based glue powder with warm water or, in the case of synthetic glue, file and sand it off. It’s important to get to bare wood for the best bond, but be careful to only remove old glue and not wood.
Using the mallet, tap parts back together. Some chair components can be held together with bar clamps, but non-parallel or organically shaped members require a band clamp to encircle the chair. Pay attention to the joints while clamping to make sure they’re coming together. And have a damp cloth on hand to wipe up glue squeeze-out. Monitor the joints for a while until no more glue appears, leaving clamps for 24 hours before taking a seat.
Too much glue will prevent joint assembly; apply sparingly.