Repairing a wooden chair that wobbles
Disassemble, clean off the old glue, and re-glue with clamps. A loose chair can be saved without buying another one, but the old glue must be removed properly before starting over.
When a chair starts to wobble, the original glue has already given way. That is the starting point: no new glue will hold on top of a dirty, loose joint. Before diving in, it is worth assessing whether it is worth the effort. I check all the joints by moving them by hand, set the chair on the floor, and shake it gently. If it creaks in several places and the wood is split at the tenon, the repair gets complicated. If the movement is only in the legs or the stretchers, there is plenty of work to do.
To disassemble, I use gentle blows with a wooden block and a mallet, never with a metal hammer directly on the piece. The block spreads the impact and prevents marking the tenon. I strike from the side opposite the joint, holding the chair with the other hand so as not to force the rest of the legs. Sometimes the old glue is so hard that the joint won't give; there it's best to apply a little heat with a heat gun or steam to soften it before persisting. If the piece resists too much, it's better to stop than to split the wood.
Once disassembled, I scrape off the glue residue with a chisel and sandpaper. The tenon has to be clean down to bare wood, without old crusts that prevent the new glue from gripping. I also sand the inside of the hole with a small stick wrapped in sandpaper, because that's usually where most of the dried glue remains. If the tenon has become loose after cleaning, I wrap it with a turn of cotton thread or add a thin wooden wedge to restore the fit.
To glue up, I use wood glue, the same kind you can get at any hardware store. I apply it to the tenon and inside the hole, bring the pieces together, and let the glue push outward as I tighten. That's where the clamps and bar clamps come in: I hold the joint and check the square with a carpenter's square before tightening all the way. If the chair has stretchers, I dry-fit them at the same time so everything stays aligned in a single assembly. Over-tightening can dent the wood, so I put a block between the clamp and the piece.
Drying time depends on the glue and the workshop temperature, but it's best to leave it alone much longer than you feel like waiting. I move the chair only when the joint feels firm to the touch, and even then I leave it a while longer before sitting on it. If the movement was significant, I reinforce the stretchers with a new tenon or a glued block on the inside, as long as the piece allows it. Not every chair is worth the work: when the wood is cracked in several places or the seat has given out completely, accepting that it isn't worth it is also part of the craft.
