How to Reglue a Loose Mortise-and-Tenon Joint

Identify shoulders, haunches, wedges and any pegs before dismantling. Do not twist a rail if adjacent joints remain sound. Old animal glue that is detached can be softened and removed selectively, while sound historic wood should remain untouched. Dry-fit the tenon to confirm full seating and shoulder contact. Replace a missing wedge with matching straight-grained timber only when its original position is clear. Apply compatible adhesive sparingly and clamp the whole frame square, checking both diagonals.

Assess before dismantling

Remove the furniture from use and inspect the whole structure in strong light. Photograph joints, fixings, tool marks and previous repairs. Apply gentle pressure only to locate movement; repeated flexing enlarges damage.

Plan and dry-fit

Label any part that must be removed and keep fragments and original fixings together. Choose a compatible, serviceable adhesive and rehearse clamps with padded cauls. The repair should close naturally without changing the furniture's geometry.

Carry out the repair

Work cleanly and remove only failed material that prevents a close fit. Apply the minimum adhesive needed, assemble in the recorded order, and tighten clamps gradually. Check level, square and alignment throughout.

Avoid common damage

Do not use household filler, expanding glue, instant adhesive or added metal simply because the joint is difficult to reach. Avoid broad sanding and keep water or solvent away from vulnerable polish, veneer, upholstery and labels.

Aftercare

Allow a full cure in stable indoor conditions, then test gradually. If decorated surfaces cross the damage, timber is badly shattered, or earlier repairs obstruct the joint, consult a furniture conservator.