Dissolving Old Glue

Dissolving Old Glue

I have a wood armchair, which was previously repaired, but not well. I would like to take the chair apart at the glued junctures and repair it properly. What is the best way to dissolve the old glue? Any help you can give me with this project would be greatly appreciated.

Michael Dresdner: Almost all wood glues will come apart with heat, often fairly low temperatures. Getting heat to the glue surface is the hard part. One of my favorite methods is to use live steam. I create the steam with a small cappuccino maker, with a gas line hose (which is heat resistant) attached to the output tube. At the terminus of the gas line is a basketball fill needle, the whole rigging attached with hose clamps. This allows me to inject live steam through the tiny hole at the end of the needle into the joint. The heat and moisture will soon soften the glue enough to take apart a recalcitrant joint. Keep a pair of gloves or oven mitts handy to handle the “steam tube” as it gets very hot once the cappuccino maker cranks up a head of steam.

Rob Johnstone: To quote Sherlock Holmes, the game is afoot! Unless you know what sort of glue was used on the repair, you will be shooting in the dark as to selecting a proper technique. One solution that will work for most common glues is steam. Drill a small hole and use a tube to pump steam into the joint. (This is a tricky operation in and of itself … but one commonly done in stringed instrument repair.) Steam will release hide glue, as well as white and yellow glues. Epoxy needs to get to 250 F in order to release … steam is not that hot. There may be other chemicals that will actually dissolve some glues and adhesives, but I am unaware of them.

Lee Grindinger: Dissolving glue can be tough. It’s likely that the glue most recently used is water-soluble at some level, but getting water to the glue itself can be a challenge. Try injecting water through a needle and keeping the joint wet. Manually wobble the joint, and once it loosens a bit, put more water to it and keep wobbling. Be sure to clean all the old glue from the joint before you reglue. Fresh glue adheres poorly to old glue.

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