Tuesday, November 8, 2016

Nana's Dining Chair Rebuild, Part 5: Shaping

With the joinery complete, it's time for some serious shaping.  This chair has a lot of curves, some of which are too sharp for my flat-bottomed spokeshave.  I started using rasps and files more as I progressed - wish I had started with them earlier.  There are a lot of photos in this post, so I'll try to let the pictures and captions do most of the talking.
Marking the legs with a template
Easy clamping in the vise for the first side, but after that side is shaped ...
... it's tough to figure out a good clamping method.  Using a bench dog wasn't good enough.
Combination bench dog and end stop still not good enough ...
Upper part of leg was still square and clamping that tightly to the bench worked well.
With a clamping method worked out, I made some stop cuts and started chiseling.  I got better and better at chiseling to the lines as the work progressed.  Much less clean up work that way.
Chiseling to the lines
Watch that grain direction - note the knot at left causing the grain to dive
Planing where possible on convex curves
Smoothing concave areas with spokeshave
Very happy with how the front legs came out.
Original and new leg
The front rail was a matter of stop cuts, chiseling, and cleaning up with rasps and files.
Old and new - still need to make the line detail
And with that, the front leg assembly was dry fit and is looking good
For the back legs, there is a broad sweeping curve on the back of each leg.  I wanted to keep the off-cut to use as a clamping caul when working on the leg, so I got out the jigsaw.  I know - hated to use a power tool.  Wish I had a good bow saw to cut this.
Aliens visited my shop.  The main reason I love using hand tools.
Using the jigsaw on the saw bench
Cleaning up with spokeshave
Marking the shape with a template
 Shaping of the back legs began with sawing away the waste on the lower portion of the leg.
A long rip cut to remove some waste
Then it was on to the stop cuts and chiseling to the curved layout lines.  After removing the bulk of the waste, spokeshaves, rasps, files and scrapers finished it off.
Smoothing the curves with a scraper
Didn't get many pictures on the leg shaping.  Oh well, on to the backrest rails.
Chiseling away some waste
I ran into a problem here.  When I whacked the chisel above, a big chunk of waste came off that included some keeper material.  It broke off at the level of the tenon.  I glued the piece back on and got back to it later.  The reason it broke off was that the chunk was unsupported behind the chisel cut. I was more careful taking much smaller bites with my chisel cuts and also used a plastic card in the kerf to help support the chunks.
Plastic card in kerf helps support the wood during chisel cuts
The lower and upper backrest rails both get a mortise to house the backrest splat.  I cut the mortises after having shaped the rails.
Lower backrest rail mortise laid out ...
... and competed.  It's 6" long, 3/8" wide and 3/8" deep, but went reasonably quickly.
Upper backrest rail shaped on its underside and mortise laid out
Closer view of layout
And the mortise completed
The next part of shaping was to make a sort of cove on the inside front edges of the backrest rails and legs that make up the backrest frame.  The cove is 1/8" deep and 1/2" wide.
Area to be "coved" marked out
Started with a gouge and cut to the lines
To clean up the cuts and make them more consistent all around, I made a small cutter for the scratch stock.  Also had to modify the body of the scratch stock so it would work properly on curved surfaces.
Scratch stock and new cutter.  Area of stock below cutter is now curved to fit concave work pieces.
Close-up of cutter, it is sharpened similar to curved scrapers
Eventually get this profile ...
... which adds nice shadow lines
Shadow lines from cove on upper backrest rail
With this done (and most of the shaping of the top of the upper backrest rail done), a test fit was done so that I could blend the backrest rails with the shaped legs.
Some work needed to finalize the outer junction of legs with upper backrest rail

Spokeshave blends the two pieces together
Last thing for shaping: need to make a panel for the back splat and shape it to suit.
Re-sawing a board to create panel.  Worked great with a freshly sharpened saw.
After squaring up the panel, it was clamped to the backrest and marked.
Marking the outline of the backrest, tenons will be added to the shape
The tools used to generate the shape - plastic tubs make great curve templates
Splat shaped and fitted
And here is the back leg assembly.  Very happy with this.
Back leg assembly shaped and dry fit

I actually have one more "shaping" step to do, but I'm hoping anyone reading this blog can suggest a way to accomplish it.  The front seat rail and the backrest splat each have a detail cut into it.  I'm not sure what to call this detail, but it's a roughly 1/8" wide, 1/8" deep slot.
The details that need to be added
Close-up on the front seat rail, where the detail follow the bottom shape
Close-up at side of splat - detail extends all around the splat
I need to get started on these things tomorrow, so if anyone out there has a suggestion ...

Anyone? ...


  1. Scratch stock and a chisel to match the width. I don't see any other way around it with just hand tools.
    BTW, I really liked how your coves came out.

    1. Thanks, Ralph. I do have a 1/8" chisel and will use it in some capacity - just not sure yet exactly how. Thinking about making an impromptu slitting blade-on-a-stick to mark out.

  2. That is such an impressive piece of work.
    Curves take so much time but they also look fantastic.

    I would probably make the slot using a hobby knife to cut the sides, and then remove the waste with a narrow blade in a router plane, or use a narrow chisel.
    I find that a hobby knife is fairly easy to control, and if you go light with it the first time for just marking the shape, the next time you can ad a little more pressure, and you will be able to make a 1 mm deep cut easily. Then just remove the wast and repeat the process till you are at the desired depth.

    I once made a really simple router plane for something like that. with a very narrow blade. But if you have a min router plane you should use that one.
    The simplest way to make a cheap fast router plane is to screw in a regular screw in the bottom of a small block of wood. make sure the head is at the desired depth. Then you file the sides away, and perhaps give it a few strokes with the file to create an angle to clear the bottom of the slot. And sharpen it.

    Good luck with the project

    1. Hi Jonas. Great tip on making the mini router plane with a sharpened screw - love it. I think I will use some combination of the tips I've gotten.

  3. Impressive work you are doing there...

    Looking art it, it look like the original was done using a small piloted bit in a tail-assistant router (the screeching kind)
    Something similar that a luthier would use; Dremel type tool in a precision plunging base, using a guidepin riding on the edge.


  4. Or even better following a pattern laid on top of it (two faced carpet tape)


    1. Hi Bob. The pattern idea is a winner. But rather than a dremel (which I don't have), I think I'll use the pattern and a knife to define the walls. Thanks.