Real-life Test: Do You Need Glue?
Before I pull my pants down and tell you how I messed up, here’s the set-up. The stretchers and legs of my chairs are built so they are in tension (I do this by lengthening the tenons in the stretchers slightly). Then, after driving the legs into the seat, I back-wedge the legs’ tenons.
The result is that the undercarriage is a bit difficult to assemble (heavy hammer blows required). But all the pieces pressing against one another also make it difficult to take apart.
Because glue is cheap, I also paint all the tenons and mortises with a coat of liquid hide glue, which is my favorite adhesive.
So yesterday I assembled the two chairs shown above. I went through my pre-assembly ritual checklist and put the first chair together. During the glue-up the glue seemed to be thinner in viscosity than usual, but I chalked that up to the fact that I’d warmed it in some really hot water so it would flow.
After the chair was wedged together, I checked the empty glue bottle. Somehow I had grabbed a bottle that expired in 2016. I didn’t even know I owned an old bottle of glue.
Had my glue gone bad? When hide glue goes bad, it gets runny and usually puts off an ammonia smell. Mine was runny. But there was no smell. And because I had used up the whole bottle, there was no way to make a test joint after the fact.
So now, 24 hours later, here is my plan: I’m going to whack the joints with a mallet and see if they pop open. If they don’t, I’m going to cross my fingers and continue making the chair.
The good news is that even if the joints fail on the chair made with the old glue, I can repair them easily and quickly with fresh hide glue. (The second chair was made with fresh hide glue.)
It’s a real-world experiment. My gut says the chair will be fine. Wish me luck.
— Christopher Schwarz