Wednesday, October 26, 2016

Nana's Dining Chair Rebuild, Part 3: Joinery Layout and Making Templates

Well, the week in Utah was great.  Over the course of five days I hikes about 43 miles, mostly in Canyonlands National Park.  What a place!  Don't tell anyone (lest it get overcrowded), but the "Needles" area in the southern part of the park is so beautiful.  Fall is probably the most popular time for this park, but I only saw a few other people once I was a mile or two from the trailheads.
View of Needles District of Canyonlands NP
I got back to the project this week.  I did most of the grunt work of stock prep on Monday and Tuesday and man, am I sore!  Today I spent making templates and very carefully marking out some joinery.
Front leg template, copied from original
Before cutting out the back leg template I drew a straight line (red dotted line) that I'll use to get a flat spot for the lower rail joinery.  The plan is to cut off the waste and plane it to the red dotted line, lay out the joint and then fair the rest of the curve (leaving a little flat spot for the joint).  This layout also gives me one of the angles I'll need when cutting the shoulders of the lower side rail.
Lower portion of rear leg
I also drew the line on the leg blanks and I'll cut and plane to the lines.
Cut lines drawn on rear leg blank
It really helps having the original chair to make templates from.
Template for lower backrest rail
Just a couple more pieces to make templates for.  Shown below are both aspects of the back leg, the front leg template and the lower backrest rail.
On a side note, look at the lower aspect of the lower backrest rail.
Bottom of the lower backrest rail
It's very rough - looks like bandsaw marks.  I can understand why the maker may not have wanted to smooth this up (because it's rarely, if ever seen), but that's where I might grab the chair to pick it up, so I'm going to make this easier on the hand and smooth it up on my version.

Laying out the joinery was slow going.  I was being so careful to mark on the correct faces, at the correct locations.  The front leg upper rail mortises were pretty straight forward.  Note in the picture that I have an extra inch or so above the top of the leg so that when I chop the mortise I won't blow out the top of the leg.  For door stiles they call this extra length a "horn" and that's what I've called it here.  I'll cut it off later so the top of the front legs will be flush with the top of the rails.
Front leg upper rail mortises marked out
In the above picture the front leg is resting on the lower legs, overhanging at the bottom by 1/2".  In a fully assembled chair, when the seat rails are parallel to the floor the front legs extend 1/2" lower than the back legs, providing a bit of backward lean when all four legs are touching the floor.  Anyway, the side rail joinery lines were transferred to the back legs directly from the front leg layout.
A closer view
After some calculations I drew in the rails and tenons.  Notice how the tenons (the smaller rectangles inside the larger ones) are offset for the side and back rails where they meet the back leg.
Side rail (top) and back rail (lower) drawn on back leg.  Notice offset tenons.
I'm going to wait to lay out the joinery for the backrest rails until I've removed some of the waste and created a flat surface to reference from.

I've put a lot of thought into the order of cutting the shapes and cutting the joinery.  I sure hope I'm not missing something.

Finally for this post, this chair has a lot of angles to deal with, primarily on the shoulders of the upper and lower seat rails.  Problem is, I only have one bevel gauge.  So I worked out most of the angles and marked them on a piece of poster cardboard.
Several of the angles I'll need to replicate
This way I should be able to reset the bevel gauge as needed.  It's not ideal, but until I get five more bevel gauges, it'll have to do.

Next up is my favorite part: cutting and fitting joinery.  Can't wait!


  1. Good excuse to hit the flea markets and stock up on bevel gauges. You just proved to yourself that you need more than one.

    1. Well, there goes my 'minimalist' approach. Seriously, I've looked into getting at least one more. Just haven't done anything about it yet.

  2. Wow, lots of angles to keep track of in this project. Looks like you are making good progress and well done on converting the assembly to better joinery options.