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2010-09-09

Sawing the back outline

Sawing the back outline
Using fret saw, I saw the back outline.
I didn't dare to use the jig saw as I didn't know if it will crack the back or not.
It was a tough job and I broke several blades.


Sawing the outline using the fret saw.


The outline sawn.

Jointing the headplate
From the cut-off I joint the 2 pieces to make a piece big enough for the head plate.
Firstly I shoot for a straight edge using my block plane.
There was some cracks in the cut-off, so I had to remove quite a fair bit of material.
As it's odd-shaped cut-off I had to think of ways to joint it.
I used 3 pieces of scraps to hold the sides, and lift up the center seam by a bit to provide the tension.
Then clamp the side support scraps onto the underlying supporting MDF.
Now when pressed in the cut-off will have some tension.
I put the waxed paper and applied the glue and press it into the fixture.
Finally clamp a piece of wood on top to press down and maintain the pressure.


Positioning the layout of the scraps.
Note the center piece is to lift up the jointing piece abit,
so that when pressed down the 2 pieces will have some pressure.


Apply the clamps for the supporting scraps


Applying the glues (I use PVA for this)


Pressed into the support. Jointed


Clamp a scrap piece to press down the center seam.

Make a 15' radius template stick
Using a pine blank, I draw out the 15' radius curve (concave and convex) and using the block plane to remove the material on the shooting board. (Convex side)
For the concave side I had to use the spokeshave to remove the material.
For graduating the curve, I use a piece of vanguard cardboard sheet and stick to the end of the block plane.
And shoot the convex like normal. With the additional cardboard thickness, it will introduce a more gradual curve.
Well it's not exactly 15' actually but a curve nonetheless.



Making out the curve and shooting the waste part


Using the spokeshave to remove the concave side.
Actually I am using 2 hands to plane the stick not 1 and my chest as the stopper.
(Ended up I got blue-black bruise on my chest the next day)
The other hand was used to hold the camera and shoot the pic.


Add a piece of cardboard behind of the block plane to introduce a curve into the planing


Can see the curve here

Thicknessing the Top and Back
I tried to thickness the top and back but experience some tear out.
My luthier friend Alex advise me to use a high angle plane and find the direction which minimise the tear out.
Then I tried diagonal and adjust the plane, indeed the tear out is minimised.


Thickness using my mujingfang block plane using a pull stroke


Some tear out in the planing


Thicknessing the top using my Stanley block plane