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Mahogany Kitchen Stool Project

Well, here we go. I have been working on the design and preparation of this project for 3 years. The final prototype was just completed.



This is my second prototype. The first one was a quick (that is a relative term) mock up to see if I had the size correct. I built this out of scrap 2×4s and screws. Pieces were only roughly shaped. After building this, we determined that it was about a half inch too tall.



The second prototype was built as a prelude to actual construction. Each stool has 42 mortise and tenon joints. Several of them are angled and others are on curved parts. By making a full prototype, I have a scale pattern to verify the layout of each piece before I cut into my lumber.



Also, I get a chance to make mistakes and learn. I ended up missing on three or four dimensions and had to patch parts up. I have chosen to form the curved parts by laminating thin strips. The two curved boards on the back formed very well, but the 5 slats did have some spring back. I'll need to adjust the form or move to thinner strips. Stay tuned on that one.

Finally, I get one last chance to check my design choices. In this case, my wife and I felt that the slats on the back were spaced a little too far apart. It ended up crowding the gap to the legs. I changed the design and moved the slats a little closer together.

I'll outline how I intend to proceed with this blog. I'll post updates on the construction as I go. Woodworking is a spare time activity for me. Weeks may go by with only a little activity. I'll post a few "flashback" entries where I will cover my design process.

I'll also keep a log of construction hours. This will not include design or prototyping time.

Cutting rough stock : 2 hrs
Cutting legs to width and thickness: 4 hrs 20 min
Cutting thin stock for seat back laminations: 3 hrs

Total so far: 9 hrs 20 min
That's a very nice design. The large surface areas will really showcase the mahogany. What finish are you considering? As a pending chair builder, I will be "glued" to the screen…
 

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Mahogany Kitchen Stool Project

Well, here we go. I have been working on the design and preparation of this project for 3 years. The final prototype was just completed.



This is my second prototype. The first one was a quick (that is a relative term) mock up to see if I had the size correct. I built this out of scrap 2×4s and screws. Pieces were only roughly shaped. After building this, we determined that it was about a half inch too tall.



The second prototype was built as a prelude to actual construction. Each stool has 42 mortise and tenon joints. Several of them are angled and others are on curved parts. By making a full prototype, I have a scale pattern to verify the layout of each piece before I cut into my lumber.



Also, I get a chance to make mistakes and learn. I ended up missing on three or four dimensions and had to patch parts up. I have chosen to form the curved parts by laminating thin strips. The two curved boards on the back formed very well, but the 5 slats did have some spring back. I'll need to adjust the form or move to thinner strips. Stay tuned on that one.

Finally, I get one last chance to check my design choices. In this case, my wife and I felt that the slats on the back were spaced a little too far apart. It ended up crowding the gap to the legs. I changed the design and moved the slats a little closer together.

I'll outline how I intend to proceed with this blog. I'll post updates on the construction as I go. Woodworking is a spare time activity for me. Weeks may go by with only a little activity. I'll post a few "flashback" entries where I will cover my design process.

I'll also keep a log of construction hours. This will not include design or prototyping time.

Cutting rough stock : 2 hrs
Cutting legs to width and thickness: 4 hrs 20 min
Cutting thin stock for seat back laminations: 3 hrs

Total so far: 9 hrs 20 min
If you're nervous about gluing the four legs square to each other, keep in mind that good joinery will force the legs toward square. It should also be relatively easy to measure the diagonals and clamp the long side a bit and remeasure. Just don't be too hasty about popping the chairs out of the clamps like I tend to do. It takes several hours at 50F for Titebond II to cure in my garage. Also, make sure your glue-up platform is flat.

At least your chairs are square. Rodel's are trapezoizal. Hopefully, squaring them will be the same process…
 

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Mahogany Kitchen Stool Project

Well, here we go. I have been working on the design and preparation of this project for 3 years. The final prototype was just completed.



This is my second prototype. The first one was a quick (that is a relative term) mock up to see if I had the size correct. I built this out of scrap 2×4s and screws. Pieces were only roughly shaped. After building this, we determined that it was about a half inch too tall.



The second prototype was built as a prelude to actual construction. Each stool has 42 mortise and tenon joints. Several of them are angled and others are on curved parts. By making a full prototype, I have a scale pattern to verify the layout of each piece before I cut into my lumber.



Also, I get a chance to make mistakes and learn. I ended up missing on three or four dimensions and had to patch parts up. I have chosen to form the curved parts by laminating thin strips. The two curved boards on the back formed very well, but the 5 slats did have some spring back. I'll need to adjust the form or move to thinner strips. Stay tuned on that one.

Finally, I get one last chance to check my design choices. In this case, my wife and I felt that the slats on the back were spaced a little too far apart. It ended up crowding the gap to the legs. I changed the design and moved the slats a little closer together.

I'll outline how I intend to proceed with this blog. I'll post updates on the construction as I go. Woodworking is a spare time activity for me. Weeks may go by with only a little activity. I'll post a few "flashback" entries where I will cover my design process.

I'll also keep a log of construction hours. This will not include design or prototyping time.

Cutting rough stock : 2 hrs
Cutting legs to width and thickness: 4 hrs 20 min
Cutting thin stock for seat back laminations: 3 hrs

Total so far: 9 hrs 20 min
Oh, if you're in the same trapezoid situation, then I would recommend loose-tenon joinery. If you make the mortises perpendicular to the mating surfaces, then regardless of the angle the pieces make with each other, the joints will be "square". I found this out when making that Ipe bistro table a few years ago that had legs at a 3 degree angle, so the aprons had to match.

I've made my own router jigs and loose tenons in the past, but I think I'm going to give the Beadlock Pro system a test-drive for my first chair.
 

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Begin Rough Cutting

Back in early November, I went to my favorite lumber yard and started looking at what kind of wood to use. I was interested in mahogany, but wanted to check out my options. They had some very nice ribbon mahogany. I went home and gave it some more thought. The next weekend, I made the plunge.



I had only one problem, I kept seeing pieces that looked too nice to pass up! I ended up with way more than I needed for this project. I can rationalize it that I saved gas by not making an extra trip ;) You can see 3 fir 2×4's on top of the stack. They ended up being the material for my prototype.

Even though I had plenty of material, I took it as a challenge to try to get the most use out of each and every board foot. I spent way too much time on this, but I packed in the pieces in the most compact cut layout I could. Here is the result after 3 or 4 iterations on my CAD system.



I'm hopeful I will end up with only small blocks of scrap and a big pile of sawdust!

Fast forward to last weekend. I finally was able to start cutting the legs. Here is where I ended up.



I got the width and thickness rough cut and then ran them through my planer. I learned something about my dial calipers. I bought a nice one with resolution down to 0.001 inches. The resolution makes it nice to know exactly what dimension I am at. On the other hand, I don't need to worry about being off by 0.001 or 0.002 inches. If I can't see the difference when I hold two pieces up to each other, I am happy.

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 15 min
Prepping laminations: 15 min

Total so far: 9 hrs 50 min
That is going to be one heckuva set of chairs. The prototyping is really paying off. I love to work with mahogany. It's cool seeing the red layer between the white oak layers in the dust collector bag. Great blog!
 

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While visions of perfection dance in my head

I deal with correcting mistakes instead!

It has been quite a while since my last post, but I AM still working on this project. In addition to regular life, we have had a week long vacation, business trips (including 2 weeks in China), a family illness and preparing for RAGBRAI . The shop time has been hard to come by.

I figured this would be a good time to confess and share how I am dealing with this round of unexpected issues.

Dull Bandsaw Blade

I started to shape one side of the back legs. I knew my bandsaw had a dull blade, but I got lazy and told myself that I could just leave a little extra wood. Wrong. The blade took on a twist and curved right past my line. Stopped and bought a new blade (one with a better tooth profile) and the rest of the cuts went fine. But I was stuck with one leg that needed help.

My solution was to flatten out the damaged area and glue a patch on.



After the glue dried, I smoothed the sides. The grain matched quite well.



Once I did the final shaping, there is a faint glue line that I think willl nearly disappear once the wood darkens (sorry no pic)

Router Pattern

This one was an act of real poor thinking. I had been shaping several legs and always being careful to turn the router on and off only when it was stable on the template.

Except this ONE time.

I lifted the router while it was on and the bit cut into the pattern :( The solution here was automotive body filler (Bondo).



The filler was applied to the cut and then sanded smooth.



Chipout

The base of the leg flares out and it was not a surprise that I had some chipout. Most of the time, I could find the missing piece and glue it back in. One time I had to make a patch. I squared up the chipped area and flattened it with a sharp chisel.



I found a piece of wood with matching color and glued a block in.



Mortises and Tenons

This project has a LOT of mortises and tenons. I took extra time to draw each mortise and then I would check it against my pattern piece.

Foolproof - right?

Wrong!

Every once in a while, I would forget to check a piece against my pattern. As luck would have it, one time I skipped checking was on a part where I had shifted the mortise location 1/2 inch. Back to gluing patches… I came up with a fairly creative soution to apply pressure while the glue dried. Luckily, this particular joint has a tenon shoulder that will completely cover this patch.



I managed to cut a tenon or two a little thin. More patches. These are completely hidden inside the mortises. I should point out the black dot on the end of the tenon. This is my technique for preserving the orientation of each piece. The black dot is always in the top right front corner of each piece.



The Big One

When I first did the rough cutting of the legs, I had one kick back incident. The only damage was the blade dug into the side of one of the legs. I saved the scrap from shaping the leg to get a good color match.



I used my laminate trimmer to create a pocket of even depth. Then I created a paper pattern by rubbing a pencil over the recessed area. I cut a thin slice off my patch piece and placed the pattern to match the grain.



It took a while to get the patch shape to match the cutout area. Lots of hand filing.



I glued the patch in place with just a little extra thickness. A little sanding and this is what I ended up with. I had hoped for a little better color match, but it is down next to the floor so hopefully it won't be too big of a distraction.



I have been cutting a lot of motises and tenons. Not the most thrilling blog material, but I'll try to show where I am with my next post.

Current time log:

Cutting rough stock: 2 hrs

Legs
> Cutting to width and thickness: 4 hrs 20 min
> Cut to final length: 3 hrs 30 min
> Shaping: 5 hrs 50 min
> Mortises: 10 hrs 35 min

Seat Back and Back Rest
> Cutting thin stock for laminations: 3 hrs 35 min
> Prepping laminations: 8 hrs 40 min
> Glue up Laminations: 3 hr 50 min
> Trim Laminated Parts: 2 hr 25 min

Back Slats
> Cutting thin stock for laminations: 1 hr 55 min
> Prepping laminations: 3 hrs
> Glue up Laminations: 6 hrs 5 min
> Trim Laminated Parts: 10 min

Lower rail parts
> Cut to width and thickness: 10 hrs
> Cut to length: 1 hr 30 min
> Tenon: 13 hrs 20 min

Total so far: 78 hrs 45 min (13+ hrs per stool)
Thank you so much for sharing the OOPS! moments. I think that's what makes this site and it's contributors so amazing.
 
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