Furniture repair and refinishing often entails disassembly, and that may be a headache with glued joints. If you simply attempt to drive them apart, you are just less likely to split the wood as you are the adhesive, sometimes more so. The best plan of action is to soften the paste with a solvent first. Water or white vinegar will do the task on familiar white carpenter’s glue, and vinegar will dissolve animal-based hide paste that you are very likely to find on older furniture. Use acetone or denatured alcohol should you suspect the joint has been glued with epoxy or urethane.
Drill evenly spaced holes to the joint with a 1/8-inch or smaller drill bit. For chair legs or spindles, drill four holes around the leg or spindle roughly 3/4 inch to the wood. For flat or square discs, drill holes along each glued border. The holes should penetrate the paste to work.
Fill out a syringe with warm water, white vinegar, acetone or denatured alcohol, based on the type of paste you are trying to soften. If you are not certain, excavate a little around the joint with an awl. White adhesive breaks apart more easily than epoxy or urethane, while hide paste has a softer, more pliable texture compared to the other types.
Orient the piece you are disassembling on the work table so the holes are facing down. Inject the solvent into each hole and wash off the surplus that spills out with a rag. Allow it to work for 10 to 20 minutes.
Twist or stone the wood lightly to loosen the joint. When it has enough play, pull the joint apart. Inject more solvent if the joint will not move, wait another 10 or 20 minutes and then try again. If you are disassembling a through foliage, tap lightly on the other end of the peg with a little hammer.
Use a heat gun if you don’t make any progress with the solvent. Point the gun straight in the joint and stone the wood as the joint is warming up. When it becomes pliable, remove the heat and pull the joint apart. Sand the edges of these holes after disassembly to smooth the gouges you made together with the drill.