Tuesday, May 24, 2016

2nd Annual June Chair Build - How I Glue Up a Panel

For my chair in the upcoming June Chair Build, I have this crazy idea to do a pair of chairs with zebrano (Microberlinia brazzavillensis) chair blanks. You can read about it in the previous post.

I am collecting materials and prepping wood in order to hopefully get these chairs done by the last day of June. Last year June lasted until the middle of August for me.

The board is 12 inches wide, and I would rather the chair blanks be around 18 inches or more. That means in order to use this board, I will have to glue two pieces or more together.

My first step was to cut the seven foot board down and see if I could get three nice lengths, again around 18 inches long or so.
My three boards.
Unfortunately, the end of the board had two really nasty cracks that made me worry a bit that this piece would actually be appropriate.
Two big cracks in this end board.
I decided to just go for it. The big crack was nearly in the middle, anyway, and the smaller crack was pretty much straight up and down.
If this doesn't work, my chair will be a bit narrower than planned.
The big crack turned out to be no big deal. Runout on the board was my friend, this time. the broken piece peeled off, and I suspect will make no difference in the final look of the chair.
Less work for me later!
The other half turned out to be more of a problem. The good news is while it runs down about 1/3 of the length, it only shows on one side.
This crack is a bit more serious.
I think it will be OK, though. My plan is to inject it with epoxy, then stabilize it with some butterfly keys. Depending on what it looks like, this side can go on the bottom and not be seen.

Moving on to the "how-to" part. The first step in gluing a lamination is to plane the mating surfaces as surgically perfect as possible. I then dry-fit the joint and test for any wobble, gaps, or other signs of a less-than-surgically perfect joint. Also, I hold a straight edge up to one face to make sure we are mostly straight. If not, adjust the angle on one of the joints to match. Straightening here is much easier than flattening a warped glue up later.

Enjoy this photo-essay of my process:
Squirt some glue on one or both of the surfaces.
FYI, I happen to be using fish glue here. I like it's hide glue like properties, plus it has a longer shelf life and a faster set up time.
Spread the glue over the whole surface with a piece of scrap.

Wiggle the top board on the bottom until it sticks. This is a "rub joint."

Now you can breath. Us a wet cloth to clean up the squeeze out.

For extra strength I will clamp the joint tight.
Since this will be a chair seat, I use clamps here. It isn't always needed. I usually clamp my rub joints if I have to move them. I would leave it as is in the vise if not. Here I lightly apply one clamp, then lightly apply the other. Make sure the joint is still flush, then tighten it down.
Two clamps is plenty for this size of panel.

That's it!
Done. If you need to, remove the clamped assembly for storage while the glue dries. I'll leave this over night just to be on the safe side.

I think these panels turned out very nice, and the glue line isn't obvious. We'll see if it stays that way after I carve the seat, but I am hopeful. Normally, I wouldn't recommend a panel with an off-set glue line for a chair seat, but in this case it economizes material, and looks good (so far).


  1. That piece of wood is simply gorgeous!
    Fish glue! but is the strength as good as hide glue?

    1. I haven't had a problem with it yet, however I haven't tried it on a chair seat before. I suppose we'll soon find out!

  2. Stunning! I'm not sure I can see a joint line on either seat. Can't wait to see this as it progresses.

    1. Hi Matt!

      The left one, I can't either. The right one I can if I get close to it. The lines in the last photo are both about 2/3 up from the bottom.

  3. Beautiful pieces of wood for sure...
    I think your plans to use epoxy and butterfly (if needed) should do the job nicely.
    Fish glue, i have no idea how strong it is??

    1. I've been using it for about a year or so. It seems to work a lot like liquid hide glue, except it sets up a little faster in my experience.

  4. So how did it go with the glue? I'd be interested to know whether it works so I know if I can use it in case I run out of the hide glue!