I have a bottle of the liquid hide glue, and I admit it's probably 10 years old. I used it so that I'd I DID need to, I could repair it.
Making a smaller cabinet top. Jointed the wood, used my hand planes to finish the smoothing, adjusted the joints to dead tight.
Into the clamps with the liquid hide glue, came back 3 hours later, release the clamps - and one section is not holding; in fact, the whole piece wants to come off and the glue is still tacky.
Now, I suspect the glue is too old and won't hold. Just wanted a confirmation of my suspicions by someone more knowledgeable.