dining chair rehab

[ed kerns]

In a revolting turn of events I've gotten roped into rebuilding a set of dining room chairs. Every joint (mostly dowel joints) is loose, and over the years, someone has done their best to repair with assorted nails, screws and mending plates. I have just disassembled the first chair, removed all unneeded hardware and am contemplating putting it back together. My question is about how to handle all the old joints. Can I just clean up the old glue, grab my jug of TB2 and re-clamp? The wood surrounding the joints is still sound, but there has been some wear. Should I consider a thicker adhesive, with some gap filling ability? I've built a few chairs in my day, but working with 50 year old stuff is a whole new ballgame. I'd appreciate any tips!

[Cooler]

Gorilla glue will expand.  You want to wet the stock with water prior to gluing.  I used it for loose fitting dowels once and it has stood up. Remove any extruded glue before it dries hard.

[jteneyck]

Gorilla Glue has no strength in loose fitting joints, nor does TB II, etc.  Epoxy would be your best bet, but anyone having to repair them down the road is going to curse you.  Hot hide glue would be a better choice if that's a concern.  Alternatively, you could glue in some wood and redrill the mortises.  'Twer me I'd use epoxy.  

John

[ed kerns]

Thank you guys. Don't misunderstand, generally these are not terrible joints, just a bit worn. Once I clean off old glue they will be a little looser, but still a slip fit and probably tight enough that the joints won't fall apart on their own. Not as tight as I'd be looking for if I built new. I've thought about epoxy and may go that way. I also have some heavy bodied Titebond (Can't remember what it's called).
Mostly, I just want to be sure to use the best product for the job. Which reminds me, does anyone have experience with the "joint swelling" products they advertise for wobbly chair joints? I can't believe there is a magic bullet like that, but I'd be interested in hearing first hand experience.

[R Clark]

I've done a few chairs over the years, not nearly as many as some.  LOML was on a kick for a number of years and junk chairs seemed to follow her home like puppies follow small children.

I tried the joint swelling stuff.  Once.  25 years ago, or so.

I sometimes use epoxy.  But, I've had mixed success filling loose joints with epoxy.  The thing about chairs is that they just have incredible stresses at those joints; flaws in the joint are quickly magnified when they're being used.  Loose joints, even filled with epoxy, can often work loose again.

Other things I have done usually are an attempt to "put wood back" where it is now absent.  

  - I have removed the dowel from both sides and replaced it with a larger dowel.  This is not easy; getting it aligned right takes being fussy during the fitting of each individual joint.

  - I have "put wood back" by using very thin shavings glued back on to the dowel  Anything you can do to have wood fill the gap rather than glue puts you that much further ahead.  I have gone so far as to glue thin shims and then file it down to get a snug fitting dowel into an existing mortice/hole.  I think this works best if one side of the dowel is still solidly in place.

Good luck...

[adamcherubini]

TB will only work with bare wood, no old glue, and will only work with HIGH clamping pressure.

Epoxy is the right answer, but will run out of loose joints and extrude out of tight joints. You really want a little space in there, like the thickness of a piece of paper, between the dowel and the hole. Clamp the joints tight and use packing tape to prevent runout.

Loose dowelled chairs are bad chairs. Tight fitting blind mortises are Ok. Best are thru mortises, wedged from the back philly style.

[Willyou]

Use epoxy. Just remember that regular epoxy is a glue, not a filler. If you try to repair loose fitting joints with it alone, the joint will fail. If you have any loose/sloppy joints, either get some filler material from the epoxy company or use fine clean sanding dust (sometimes called wood flour) and mix it with the epoxy to a peanut butter consistency. Please believe me. I know from experience. Or talk to the epoxy company rep.
If you have doubts, try a test. Find two large dowels like a broom handle and drill a hole into two pieces of scrap that are about 1/8" larger than the dowel. Now glue one dowel in with out-of-the-bottle epoxy and let it cure. Glue the other one with thickened epoxy and let it cure. After they are fully cured, put the scrap end into a vice and pull sideways on the dowels until they fail. The non-thickened epoxy will fail and the dowel will rack out of the hole. The dowel glued in with the thickened epoxy will likely break if you can pull hard enough.

[gboot]

Thank you guys. Don't misunderstand, generally these are not terrible joints, just a bit worn. Once I clean off old glue they will be a little looser, but still a slip fit and probably tight enough that the joints won't fall apart on their own. Not as tight as I'd be looking for if I built new. I've thought about epoxy and may go that way. I also have some heavy bodied Titebond (Can't remember what it's called).
Mostly, I just want to be sure to use the best product for the job. Which reminds me, does anyone have experience with the "joint swelling" products they advertise for wobbly chair joints? I can't believe there is a magic bullet like that, but I'd be interested in hearing first hand experience.

I’ve used the joint swelling stuff on several chairs it does a good job.  I cleaned the joint as best I could but there was still enough glue residue that I didn’t trust TB to work.

[msweig]

I've used the chair glue I think you are talking about to tighten up my dining chairs. It worked well. BUT, my chairs were probably about 20 years old when I did it, and each chair ran about $100 when I bought them, but none of the joints are doweled, so all I was really doing was just getting out a bit of wiggle, not redoing the joints.

[Dave Crow]

I have used a two step repair with success.

First remove all old glue and wrap a veneer(wet with glue) ribbon tightly around the tenon. When the glue has dried, sand so that the joint is a tight fit.

Second, saw a slit centered on the tenon. Then slip a blind wedge slightly shorter than the tenon in the slit then add glue to the mortise and clamp the joint.

I hope this is clear.

Dave