There are three curved parts in each stool. These are formed by gluing up thin strips to create a thicker laminated part. The three parts are:
1. Seat Back – 7/8” thick (formed with 5 or 6 strips)
2. Back Rest – 7/8” thick (formed with 5 or 6 strips)
3. Slats – 3/8” thick (formed with 3 or 4 strips) (5 per stool)
As I plan the construction, I start to realize that I have 6 stools with 7 curved parts each. That works out to 42 glue ups. Each one requires a full day for the glue to cure. I do have three different forms, but this is still a lot of time – 30 glue ups are for the back slats. I need to get the glue up process started first. I can work on shaping the other pieces while the glue dries on the laminated parts.
The 7/8” thick parts were prototyped with 6 layers. They formed fine with no spring back. I prefer to use fewer, thicker strips and end up with one less glue joint. I’ll be testing out the first glue up with 5 strips and see how it goes.
The 3/8” slats were prototyped with 3 layers. There was some spring back that made it difficult to align parts for assembly. I need to reduce the spring back. My plan is to try to modify the form and test it with another prototype glue up.
The wood for the laminations was resawn off the Back Leg stock. I ended up with pieces about 1/2” thick and 3 5/8” wide. They were long enough to provide two pieces for the glue up. I then resawed these to give me 2 long strips. Now I am up to 4 pieces for the glue up.
I figured I would share some of the things I do when resawing. First I use a 7 1/4 inch thin kerf blade. The kerf is only 1/16”. This helps me get the most out of each piece. If the board is too wide, I need to stay with one of my larger blades. I do not have a zero clearance insert (yet), so I use a long scrap of thin plywood and clamp it to my saw table. I raise the blade through the plywood and I end up with a temporary zero clearance solution. Finally, I use a marking technique to keep track of which board each pair of strips came from.
I use my hand saw and make a set of marks across the end of the board.
In this case I have marked this piece as belonging to stool number 4. By angling the marks, I can return the two pieces to the same orientation as before the resaw cut. Each stool has 2 boards (one for the Seat Back and one for the Back Rest). I mark the second board for stool number 4 with 4 cuts, but I place them in a different spacing.
I now have strips of wood that can provide 4 pieces for my glue up, but I need 5 or 6. Fortunately, my strips are wider than I need. When I rip them to the desired width, I have two narrow pieces left over. In the case of the Seat Back, these two narrow strips can be glued together. This way all the wood comes from the same board and I should be able to keep the colors matched.
Once I let the glue dry and clean up the piece, I have 3 strips of wood. Each is long enough to give me two pieces for a total of 6 parts for the lamination.
The strip on the right is the glued up one. The Back Rest is wider. As a result, my left over pieces are not wide enough to make the third strip.
In this case, I have added a third piece of left over stock to make the strip wide enough.
This entry is long enough. I’ll cover more later.
Current time log:
Cutting rough stock: 2 hrs
Cutting legs to width and thickness: 4 hrs 20 min
Cutting thin stock for seat back laminations: 3 hrs 35 min
Prepping laminations: 2 hrs 20 min
Glue up Laminations: 35 min
Total so far: 12 hrs 40 min
-- Steve - Impatience is Expensive