Glueing a Glued Chair after Re-Glueing the Glued Glue

[Russ Filtz]

OK, I have this set of 25-yr old chairs that are/were decent quality. Solid wood w/ thick black lacquer finish. The joinery however hasn't proved to be as robust. Some of the stiffeners are simply doweled in. the main seat frame has a kind of finger dowel to increase glue area. Over time I've had to re-glue several of them MANY times! I've tried epoxy, Gorilla, sanding down and simple yellow glue. probably about two times each way! Now one chair has completely failed again. the wood is probably so hard now and impregnated with glue, how to I get this thing to stay together?

[Stephen Cherry]

I've had pretty good luck by replacing the dowels with floating tenons. Usually the dowels come in pairs, so you remove the dowels, chisel the area between the dowels, and insert a floating tenon into the hole.

[Brian Penning]

I'm quite surprised that epoxy failed. Where did the joints fail again? Glue areas or the wood?

[Russ Filtz]

It's always the glue joint failing. And it's not really a dowel joint per se, the entire round stiffeners going from leg to leg are tenoned directly into the legs, full diameter. The box shaped seat frame is made of flat stock that are also tenoned into the leg at all four corners, but with the finger type tenons (but these are only about half-depth. So no real way to "float" a dowel in either place. Have to get some photos up later.

For the lower stiffeners, I'm thinking to just use a screw countersunk from the rear to help keep the joints pulled snug. Will deface the chairs some, but they're pretty old & beat up.

For the box frame, that would be a little harder to do. There are some corner stiffeners in there already (which also come unglued), but maybe have to add some more to keep the box more rigid.

[Don Alexander]

if its like most chairs the joints are mostly end grain to edge grain joints with glue for extra optimism glue is never going to hold this type joint for long the tenon part needs to expand in the hole to be tight then it will hold till the wood shrinks down again
chairs have been made this way for along time soft woods tend to have a fair amount of movement and therefore joint failure is common while hardwoods in general are more stable and therefore the joints tend tofail less often