After a day of work at Lee Valley Tools, I came home and found myself in my shop with a bit of time. I had a simple project already started and only a little more work remained before assembly. I finished cutting the 6mm mortises with my Festool Domino Joiner and began the glue-up, which consisted of five rails attached to two end caps with floating tenons.
It was a simple, straight-forward assembly process. Or so I thought.
I started by applying glue to one mortise in a rail, driving in a tenon, and continuing until all the floating tenons were installed. This way, I knew that the floating tenons were already seated and I didn’t have to worry about the open time of that glue.
Next, I applied glue to each mortise of one end cap and used my dead blow mallet to drive each rail into place. This wasn’t particularly easy, so I drove them in as far as they wanted to go before starting the second end cap. Besides, aligning five mortise and tenon joints at the same time is very hard – it’s much easier to set them in one at a time, as is the case when they protrude different amounts.
With glue in each mortise, I began tapping the end cap into place, carefully aligning the Domino tenons with the mortises as I went. I got all the tenons started into the mortises, and then my 2-pound mallet started bouncing off of the assembly. Not good.
I reached for a pair of my favourite Jet Parallel Bar Clamps and started turning the handles to close the joints. Nothing moved. I kept cranking, applying as much torque to the handles as I ever have – so much, actually, that the whole assembly was trying to flip over itself.
As I applied all the force I could muster, I looked around the shop, wishing that I owned some heavy-duty I-beam clamps. There was no reason that this much pressure should have been required to close the joints. I hadn’t applied an excessive amount of glue that would keep the joint from closing. My Domino Joiner was set up to cut adequately deep mortises. Yes, it was. Perhaps the joints were so tight, the glue and/or air had no way of escaping the mortise and that was keeping the joints from closing.
Not having much luck, I added a third clamp for additional clamping force and weight to keep the assembly from flipping. I kept cranking and cranking. This was becoming more work than I’d done in the whole day up until now!
I applied a fourth clamp, moved the assembly to the floor and used my body weight to keep the assembly flat on the floor while I cranked on the handles. The assembly groaned, creaked and popped with every rotation of the clamp handle. Those were scary sounds, but they were reassuring since they indicated that something was moving. Or that it was about to explode.
After a ton of nerve-wracking creaking and 15 minutes of frantic work to pull the assembly together before the glue set, the gaps finally closed. I collapsed on the floor, exhausted. Or, at least I felt like doing that.
8 thoughts on “Unforeseen Challenges”
Sounds like a near disaster. Any idea what went wrong and how to avoid in the future?
Near disaster is right, Jim! The Dominos were a tight fit in the mortises, and perhaps fitting five at the same time was the trouble. When making the mortises with the Domino Joiner, I usually make only one tight all around and make the others wider for ease of assembly. I didn’t have that option here. I suppose I could have trimmed down the Dominos to make them easier to insert.
I know that the open time of the glue (15 minutes) was not on my side, and more than once I thought that I was stuck.
How to avoid it in the future? Use a slower-setting glue, *ahem* dry-fit, cut looser joints, or choose a different type of connection.
Wow, and I thought air compresses. I wonder if you would have had that problem using a ring porous wood. Me thinks, no.
That’s an interesting thought, that the open pores of a different species of wood would allow any pressure built up to escape.
Glue up dimensia! Glad it turned out.
What glue were you using? Rumour has it that hot hide glue lubricates the joint when going together, and PVA seizes. My hot hide glue experience as been restricted to long grain to long grain so far. SOmeone with firsthand knowledge might weigh in to say whether the rumour is true.
I was using Lee Valley’s 2002GF PVA glue. I find that PVA is slippery at first, but then gets tacky – that’s why I like to rub my PVA edge joints together for a bit before applying clamps – less chance that they’ll slide.
Like you, I’ve not used hide glue for joinery work.