Tuesday, June 13, 2017

3rd Annual June Chair Build - III

We have another June Chair Build entry completed. Greg did a great interpretation of three legged Moravian back stools made from plywood. Congratulations, Greg! For a prize, you get to sit in two brand-new chairs!
Greg's chairs are already finished!
Bob has joined us and is making posts from his blog, The Valley Woodworker, too. Being that he started his project on the 11th of June makes me think he is a bit more in to the true spirit of what we are trying to achieve here (I think I finished my first June chair on June 39th of the first year, or somewhere along those lines).

Me? Well, I've been plugging along. I finally finished up the legs today. I think these ones turned out better than any I have done to date. I did my best to be as precise as possible. It could make a difference. I think that chair legs do not have to be perfect, but have to look octagonal. These aren't perfect, but they are much more uniform than any octagonal legs I have made previously.
Eight legs looking for some chairs.
I really spent some time making the tapers four square and truly square, then ensure the octagonal bits were as square as I could. Normally the octagonal part I just do by eye until they look pretty much all right. Once the chairs are done, we'll find out if the extra effort was worth it.

Here is how I made the legs octagonal:

First, I made an octagonizer according to Greg's instructions on his blog, except instead of a scratch pin I made a hole for a pencil. This gauge is nearly the same as the one Olav the Great gave me a couple years back. Overall I would say Greg's tool is easier to make than it looks, and perhaps easier to make than Olav's. However, Olav's works better with a pencil. You can see in the photo below how short the pencil had to be.
My interpretation of Greg's octagon tool.
With the pencil tip having to be so short, the pencil mark left is fat. This is OK, as I treat these lines as a guide to get close to until it looks right.

I've also started using a jointer and a smoother since I have them in my tool chest. I could have done these all with the BU jack, but I wanted to try out the Course, Medium, Fine technique.

This was great! I was able to leave all my planes at one setting. Also, with the jointer and smoother both having cap irons, I was able to eliminate all tear out, even on the spots with crazy grain and over knots.
Medium (Yes, the #8 is overkill)
If there was a spot with crazy grain and tear out after using the jack plane, I would start the jointer a little sooner and take a few more swipes with it. Then, the smoother just had to come in for a swipe or two for a nice glassy surface. These legs are now ready for finish.

Here is how the shape of the octagon came out on the last leg that I did.
Not perfect, but pretty good.
You may note that there are a few knots in my pine chair legs. Chair legs should be made of the strongest stuff you can get. That's what I've done here.

My point was to make chairs out of home center materials, and the home center here doesn't really have an economical alternative to these. They started life as 2x2 eight footer construction lumber. I cut them up the best I could to mitigate weak spots with knots. Most of the visible knots are at a glancing angle to the chair leg, so I think those knots are not that structurally damaging. Only one has a knot that goes straight through. I tried to put that knot in a part of the leg that was thick, hoping the extra mass there will survive the Tony test.

In a way, these legs are an experiment to see if they will hold up over time. It's not best practice, but there are plenty of chairs in the world with legs made of MDF, so I predict they will sit. At least for a while.

Next up is to make the seats from 18mm laminated pine. You know, the stuff wrapped in plastic!

There's still plenty of time left in June for you to build your chair. Let me know what you are working on!


  1. Excellent progress! Glad to see chairs shaping up and putting pressure on the rest of us...

    1. You could be the first to finish two projects in June.

      Except Greg beat you to it.

  2. Great looking octagonal legs.
    I like the idea of using three planes instead of changing the setting for every operation.

    1. I think doing it all with one plane is a great way to get to know your plane, and if you don't have multiple planes it is good to know you can get it done, but since I have them...

  3. Glad to see you gave the octagonizer a go. Yep, works best with a pin. I use it to mark the distances and then use a pencil and finger gauge to lay down the lines.

    Your legs look great! Shoot for perfect and accept any variances. The variances are all but undetectable in the finished product. I have a Don Weber video and he simply knock the corner off.

    I think my pitiful offerings win me a participation ribbon at best. They turned out OK and sit decently. The form is a bit jarring for a lot of folks though. Somebody on Instagram pointed out that they looked a lot like a Sligo chair. Yea...had to Google it too, but he was right. So maybe I'm not totally out in left field with these.

    1. Thanks, Greg!

      Olav made one of the octagon I Zero for me a couple years back, and his uses dowels for stops. Perfect for use with a pencil. But, it still isn't perfect, and should be used along with your eyeballs.

      I hope my chairs turn out half as nice as yours, but I'm worried.

  4. Looking good with half a month to go. Love the feel of pine after a good smoothing plane.

    1. Hey Jeff!

      Thanks. Me, too. And the smell. I love the smell.

  5. Enjoying watching this build! I tried a construction grade lumber stool last month (SPF). Octagon seat with octagon legs. worked well and held my weight (210lbs). I put the small taper end to the seat/mortises. Ended up with cylindrical 3/4" through tennons wedged in place. Then my nephew got a hold of it and thoroughly 'nephewed' it. Either rocking or jumping resulted in 2 sheared tennons. This was my first attempt and my construction was definitely not flawless, but I'm curious to see how you handle the tennons when you get there and what size you use (mine was likely quite undersized). Thank you for sharing your build!

    1. Thanks for the comment. I usually try to make legs with the straightest grain possible. I'm a bit worried about these ones with a couple of them having knots.

      I'll orient these legs the same as yours, but I'll use tapered tenons. That should add a bit of strength.

    2. Agreed. Straightest grain possible is best. As long as the knots are not just below the seat (as the leg exits the mortise), you should still be ok. the most stress on the leg should occur from the longest lever (leg on floor to bottom of chair) and it would also take the most bending force ('moment force' if I remember my university classes correctly) where the fixed point in the chair bottom exits into the flexible or moveable member of the chair leg. Either way, you'll have a chair at the end of this and maybe some questions answered for the rest of us about building with construction grade lumber. Thanks again!

    3. Thanks. I feel a lot better about these legs now. I purposely put the knots that could weaken the structure of the chair leg as far away from the joint as possible.