Reversing Titebond Liquid Hide Glue
Sometimes I’m given every opportunity to spot a bad idea coming, and I do it anyway. I have some offcuts of bog oak from the Fenland Black Oak, a very kind and generous gift. I’ve been trying to think of a good use to put it to. It hit me one night. I could use some of a smaller piece to make the wedges for my daughters stool. If it’s fit for a Queen’s table, then it will do for my little princess’s stool.
2 days later Chris Schwarz wrote about how terrible bog oak is as wedge material….. I hummed and I hawwed, and then I decided to do it anyway. Chris is right. Bog oak is awful wedge material. I thought I just about got away with the first wedge, but only barely. Then I sawed extra large kerfs in the next two legs, and was very careful and gentle tapping them home.
A day later I flush cut the tenons… I did not get away with the first wedge. It barely penetrated the maple seat. After I scraped the surface, only half the tenon had any wedge. The leg was in there good and tight, but it looked awful. My saving grace is that I used Titebond liquid hide glue, in theory it should be reversible. I hoped for a second change to do a neater job.
I had a busy week, and did not manage to make it into the shop for days. Saturday night an old friend was in town. As is our habit, we drank a lot of whiskey. A rather wonderful evening. I staggered home, quite drunk, but not at all tired. That’s when I decided to venture into the shop….
You need 2 things to get into a joint and loosen hide glue. Heat and moisture. There is only so much trouble you can get in with a bit of non alcoholic moisture, but heat is another thing entirely.
My original plan was to put the stool upside down. Soak a cloth in water and wrap it around the leg. Then aim the heat gun at the rag. The theory was that this would prevent the wood from getting scorched. In practice, this heat gun is a bit of a beast. In under a second it dried out the cloth and set it on fire….
I’m not the tidiest woodworker in the world. I found myself desperately trying to whack out the flames while dancing in a pile of shavings and excellent tinder. Thankfully I managed to get it out, and my house is still structurally sound…
My next bright idea was to use the heat gun directly on the wood after spraying it down with water. How bad can it be? It can scorch the wood damn near instantly, that’s how bad it can be.
Finally I settled on soaking the underside of the seat with a spray bottle of water I keep around for my waterstones, and continually spraying as I heated the leg. The heat gun regularly won that race, so if the seat started looking dry, I aimed the heat gun away and re-soaked. After about 10 or 15 minutes, I flipped the stool right way up, put a chunk of small dowel on the top of the Tenon, whacked it with mallet, and the leg popped right out far more easily than I expected.
Mission accomplished, a rare moment of clarity and common sense overtook me and I decided to leave putting the new wedge in for a different, more sober, day.
That day came. I sawed a far larger kerf for the tenon, re-glued the leg and drove it home without incident. When it came time to flush cut and scrape, all looked well. The top of the tenon shows a little bruising from the dowel being driven into it. I might need to find a better way to get the leg moving if I ever have to do this again.
Lesson’s Learned:
- Titebond liquid hide glue reverses pretty easily
- My heat gun is a savage weapon, and I should not go near it inebriated
- Bog Oak does indeed suck as wedge material
I’m calling the experience a win.
Bog Oak does indeed suck for wedges. Saw a wider kerf than usual. Start off very very gently, support the wedge with your fingers as you tap it home, and gradually increase the force of the taps. And it will still wind up looking like this when you are done. I neglected to take a photo of the finished seat, but only half of the top of the kerf wound up with any wedge in it the first time I tried.
I believe black and decker lost a bid for a flamethrower contract and just sold this thing to the unsuspecting public instead. Just about anything I point it at begins to smoulder in seconds.
Exhibit A. This cloth was soaked through, and in the blink of an eye the water evaporated and it caught fire.
Exhibit B. I soaked the seat, pointed the heat gun at it, and within a few seconds it evaporated all the water and left a nice little scorch mark. Continuous spraying turned out to be the way to do it.
1o or 15 minutes of heat and spraying. A tap on the end with a mallet and dowel, and out pops the tenon.
And pretty neatly too. A lot of the raggedy stuff here is glue. Very little wood loss in the process. The tap that freed the leg would not have been strong enough to break wood.
The end of the reglued and re-scraped leg. A little bruising, but otherwise pretty damn good.