I regularly re-glue chairs. A friend of mine says there are two types of chairs -- chairs with loose joints and chairs that will have loose joints. (Rule 1)

First, rule out Gorilla Glue and other polyurethane glues. I've seen lots of failures and botched attempts with this. Under no circumstances would I use this.

I do not like to use epoxy except for special circumstances such as needing voids filled and the chair is unlikely to last until the next need to re-glue. It's also, IMO, not quite as reversible as other glues like PVAs (see Rule 1)

My favorite is to use white PVA like Elmer's. The reason I like the white is that it doesn't grab as quickly (AKA initial tack) and allows me to do a complex assembly and still do some alignment and squaring when it's all together. If it's just a joint or two, I wouldn't have a problem using Type I (Original Titebond, Elmer's Carpenter's Glue) or Type II (Titebond II or Titebond III, Gorilla Wood Glue (the off-white type))

If the chair is an older chair originally done with hide glue, I'll often use hide glue to re-glue as it reamalgamates itself. Hot hide glue has short closed assembly time, liquid (cold) hide glue has extremely long closed assembly time.

If I can't get into the joint, or it's too complex to get into the joint, I use Vertitas Chair Doctor glue. It's thin viscosity lets it wick in, swell the wood, and create a tight glue line.

Lots of choices...

I'm not so sure about Rule #1, I've seen quite a few real Windsor chairs that aren't showing any sign of loose joints 150-200 years later. What's key in a real Windsor is that the joints do not rely primarily on glue to stay tight.

If the original tenons were cut undersize you can improve the joint by incorporating a hidden wedge when re-gluing. Cut a slot in the tenon and insert a small wedge that is driven home as the joint goes back together, expanding the tenon to fill the hole and wedging it in place. If one joint has failed the rest probably aren't far behind, so taking the whole chair apart and reassembling it is usually worthwhile. For chairs of any value I strongly prefer hot hide glue because it can readily be re-glued in the future, can be disassembled as needed, doesn't require complex clamping through long setting or curing times, and makes a very strong, rigid joint. I can't say the hours I've spent getting Elmer's glue off of parts so they can be repaired have been happy ones.

The faked wedged tenon scam is just too bizarre to believe!

I have used "Chair-Loc" with pretty good sucess.

bobsmyuncle, what a great list, w/ so much useful info!

Me, I've never heard of hide glue. I'll have to investigate.