Thursday, November 10, 2016

Nana's Dining Chair Rebuild, Part 6: Some Details

I'm stoked!  Jazzed!  Chuffed (for our British friends)!!

At the end of the previous post, I asked for suggestions about how to add the recess details to the backrest panel and the front seat rail.
Detail work on the original chair
Thanks to the help I got from Ralph, Jonas and Bob, the job got done.  It took two days - one day to think about it and one day to do it - but the job is done.

Yesterday I tried a bunch of things in laying out the patterns.  For the seat rail, I started by drawing points exactly 5/8" up from the bottom, but not straight up - the points were perpendicular to the bottom at each point.  After connecting them with a curve, it didn't look quite right.
Experimenting on the template - not quite right
Then I realized that whoever made this chair originally used the exact same template to mark out the detail as they did for the rail's bottom edge.
A very close match
The original builder probably drew in the shape from the template and then freehanded a powered router with an 1/8" bit.  The small inconsistencies lead me to think it was freehanded.

So I drew the shape on my work piece with my template 5/8" up from the bottom.  Then made many marks 1/8" below that line and connected the points either freehand or with the help of some French curve templates.

For the backrest panel, I experimented with making a template based on the original chair.  I made a rub of the original to get the outline.
Made a rubbing of the original backrest splat
Close-up view
This worked nicely, but I realized that just as the original backrest panel was not symmetric, the detail that I'm trying to reproduce was also not symmetric.  So I ended up generating the curve myself.  I used a compass to scribe a "parallel" curve along the sides 5/8" in from the side.  At the bottom I had to adjust the setting of the compass to account for the tenon.  At the top I had to wing it.  After getting the corners to look right, I marked points 1/8" outside of this shape and connected the dots.
Generating the shape of the recess
Now it was time to knife the lines.  I experimented with making a twin blade cutter, but abandoned the idea.
Thought about making a double bladed cutter, the blades set just over 1/8" apart
I tried cutting freehand the lines for the front seat rail on a piece of scrap.  The freehand cutting was OK, but trying to chisel out the waste was horrible.
First attempt on scrap
This morning I bought a set of French curves, something I've thought about getting many times.  I needed something to guide my knife when cutting the outline of the details.
Using a plastic French curve to knife the lines
This worked well, but was slow as I really didn't want to mess up the parts at this stage.  With the lines knifed in, I needed some way to remove the waste accurately and to consistent depth.  Jonas had commented about making a mini router plane from a block of wood and a screw.  This got me to thinking and this morning I had an idea,

I took a squared-up 1 1/2" x 3" and marked, sawed, and planed a 45° angle on the end.  Then I marked a 1/8" slot on that face.
45° end on a 2x4 with 1/8" (strong) slot marked out
After sawing and chiseling out the waste, a 1/8" chisel fit in the slot so that the body of the chisel was proud of the surface by 1/16" or so.  Then I screwed another piece onto the angled face to lock the chisel in place.
One mini router plane, coming right up!
Side view
Close-up view of the chisel extending down below the base
I couldn't wait to try it, but first I had to chisel out some waste to leave a hump in the middle of the recess.
Chiseling out some waste first
And then - are you ready for this? - I started routing.
Routing out the recess
Holy crap, this was exciting!  And it worked extraordinarily well, though I had to take very small bites and many passes.
Look at the little curly shaving!
I ended up going about 3/32" deep and used a piece of sandpaper wrapped around a plastic card to clean up the recess a little.
Front seat rail done
Backrest panel done
Like I said - STOKED!!

BTW, does anybody know what this type of detail is called?

6 comments:

  1. WOW that is impressive!
    What a nice looking router plane you made for that job.

    I don't know what that type of detail is called, "square trench" perhaps.

    Brgds
    Jonas

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    1. Thanks Jonas. And thanks for your inspiration in making the little router.

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  2. Heh good job buddy! I was a bit skeptic about knifing the double line, but, you got it done right..

    Bravo

    Bob and Rudy

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    Replies
    1. Thanks a lot, Bob. I appreciate the comment.

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  3. Overall impressive work with all those curves, angles, carving etc.
    Sylvain

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    Replies
    1. Thank you, Sylvain. I still find the curves challenging, but I'm getting better. And that's the main thing!

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