Hide Glue

 I use hide glue for most of the chair joints, save for gluing up the  seat and the hand piece ( for these I use Titebond III).  Hide glue has several advantages, chief among being the fact that it is reversible.  So if something breaks or comes loose, the glue can be taken apart with hot water and or a little judicious steam.  Then glue can be reapplied and the joint reglued, ready for another good long while.  The Egyptians furniture was glued up with hide glue, and it  is still around today.  Carpenter's glue, on the other hand, doesn't stick to itself once it's dry, so to reglue you have to scrape right down to bare wood, which is a pain, and it can cause sizing problems.  But hide glue, because it is protein based, will adhere to itself and reactivate, being just as strong as when first done.
Another advantage is that hide glue has a long open time, meaning once I start a glue up, I have about a half an hour to complete, and if something doesn't go right, I can pull it apart and check, and then reassemble, and I don't have to worry about carpenters glue grab, the way that it will seize a joint after about ten seconds and won't let go.
I cook up me own glue, which is super easy and allows me to always have fresh glue.  I use 251 gram or 305 gram glue, a measure of the strength.  305 is typically used on the neck joints of guitars and violins as they are under constant pressure.  It's the most expensive, but for a chair I figure why not.

The basic recipe is really simple, consisting of one part salt, two parts glue flakes, and three parts water.  First day, combine the two parts glue with the three parts water, stir and let sit overnight.  The next morning, cook the glue at 140 F for two hours, adding the salt once it turns liquid.  The salt makes the hide glue liquid at room temperature.  Stir the mixture occasionally.  After two hours of cooking, put in the fridge for overnight.  The next morning, heat up again at 140F for two more hours, and after that your done.  As you can see I use a double-boiler on a hot plate and a candy thermometer.  Be careful not to go over 140 as it will ruin the glue.  And always do a glue test when the batch is done, more on that in the next post.