If it is exceptionally valuable or an antique I would use hide glue so that the chair could be dismantled in the future if nessary. Just a garden varity dining chair requiring daily use,most any modern woodworking glue will be fine. I normally scrape both sides of the joint enough to insure old glue doesn't obstruct assembly. There was a time I felt all old glue should be removed. Experience has shown that if the joint isn't worn,total removal isn;t nessary. If the joint is loose and/or has previous attempts at repair I remove most if not all old glue. If I plan to shim the joint I may as well remove old glue to alow better fitting. Hand made and antique joints are shimed with hand plane shavings. Otherwise I also use cotton string,cloth and saw dust x glue. I have tested expanding urathane and found it isn't strong enough. Others report success glueing poorly fitting joints with urathane filling void. As far as I can tell,urathane mixed with dry saw dust assembled in a wet joint is not much stronger than saw dust and pva glue.

PVA glue? Chairlock good or should I get the Gorilla Glue?

When chairs are coming apart I find it's usually an issue of a poorly fitting joint rather than glue failure. A glue that is gap filling with structural strength is a solution that can work, at least for a while, on a non-valuable chair. A 20 min or 1 hr epoxy will do this. Better is to make the joint tight. One way I do that is to make a hidden wedge in the tenon-- split the tenon with a saw kerf then make a wedge that will push into the kerf as the joint is driven together, slightly expanding the base of the tenon in the bottom of the mortise hole. A little tricky to get right, but works quite well. I like hot hide glue for chairs because it is strong and rigid, but easy to take apart if things loosen up again in the future, and can be re-glued without losing wood by sanding etc for clean-up. With most other glues you need to get back to wood to make a good joint. I haven't found anything better than sandpaper around a dowel for cleanup.

If the fit is really bad (or in the case of a broken tenon) and I really care about the chair I will replace the the tenon with a loose tenon sized to fit the mortise correctly. You saw the old tenon off, drill a hole into the end of the stretcher and glue in new wood to make the joint. The loose tenon can be made with different diameters at each end, depending on what you need to do to make things work.

I've always come to regret halfway repairs on chairs, now if things are getting loose I try to take the whole thing apart and make all the joints right, it is seldom the case that one joint in isolation fails.

>AGREE on this>>>
I've always come to regret halfway repairs on chairs, now if things are getting loose I try to take the whole thing apart and make all the joints right, it is seldom the case that one joint in isolation fails. I also try to do repairs that are "reversible," meaning I can repair them again some day. A friend of mine says, "There are two types of chairs, those with loose joints and those that will some day have loose joints." So I avoid epoxy (unless I know that the chair will not last for another round) and fox wedging.

There is a special room in Hell for people that put nails in chair joints and it's right next to the room for people that put screws in chair joints. These approaches keep a chair from falling apart, but do not keep it from getting loose joints. Both concentrate the stress in a small area and tend to mark the place where the wood is going to crack. Nails, especially pneumatic nails are just plan a pain in the neck to get out and almost always cause damage to remove.

Here is a link that might be useful: though it applies to doweled chairs, the principles are the same

This post was edited by bobsmyuncle on Sat, Jan 24, 15 at 12:16

Millman I must confess,I've never tried chairloc because I'm too frugal to buy products for single use unless nessary. For personal reasons I don't use Gorilla glue. PVA is a type glue made by most adhesive companies for many different applications. Franklin woodworking Titebonds are my favs.
Rgand,I agree with everything you say,esp about wedge joints being tricky to master. I actually bought a dedicated wedge jig set years ago that created a slightly flared mortise. For some reason I somtimes managed to split the rung with the wedge so I rarly make wedged joints now.
I'm carious if anyone thought it weird that I don't use Gorilla "for personal reasons". Haha haaa. I have a couple of habits that makes Gorilla a poor choice for me to use. Spreading with my finger,absent mindly scratching noise,adjusting glasses and scratching ears. Any of you tried that? Well DON"T,the stains are horrible. Looks like a mixture of a bruise and wagon axle grease and will not wash off either. Going to the office looking like you rebuilt an engune on the way will earn stares and questions. I just said "yea but did you notice I managed to keep my shirt clean." I think the ladies sitting at a table next to mine in cafeteria lost their appetites from watching me eat with dirty hands and face.

I don't care for the Gorilla Glue polyurethane much either. (And I have done work for the family that owns the company).

I used Gorilla Glue once several years ago, making bent lamination sled runners for a Klondike Derby sled. I think I've finally gotten the residue off my skin, but the shop floor and any surface I happened to touch during the process probably still show the effect. Gads, what a mess as it foamed up everywhere. Next time it will be Titebond III for water-resistant applications for sure.

Agree completely on special rung in hell for those who drive nails and screws into chair joints! -- or tables- I pulled nearly 20 fasteners out of a broken joint in a table we rescued for my son. Replacing the wood to fix this correctly was about a 15 min job, pulling the nails and screws took 4 hours.

Also, and I tried to say it carefully, but I'd only use epoxy on a throwaway piece being rescued from the dumpster--chairs you want to keep will need reassembly every few decades or centuries (we have some ~200 year old windsor chairs down at the church that are so nicely tensioned that they probably don't need glue at all to keep them together).

Thanks guys, I did not realize that Gorilla Glue was polyurethane (been out of the retail bushiness for about 12 years) but I do know first hand about the mess PL Premium makes and this sounds very similar.

Gorilla Glue is a company. It's original product was a polyurethane glue. They now have a type II PVA glue and several varieties of CA glue under the same label. Their HQ is about 7 miles due south of me. It's parent company is Lutz File and Tool that also bought Millers Falls.

rwiegand said "Agree completely on special rung in hell for those who drive nails and screws into chair joints! -- or tables-"

Should they be any closer to the flame than those who use tub & tile caulk for everything including but certainly not limited to window glass replacment in place of vinyl,nuts in place of loc-tite,wood repair in place of glue,wood repair inplace of wood filler,facuet installation in place of plumber's putty and as the soulution for poorly fitting items.