03 June 2013

Drawknife grinding

Old drawknives are supposed to be found cheaply second hand.  When I looked on internet the online prices were not that good. Besides the the relative high price they are supposed to be a major grinding job anyway.  So I went for a new one. No luck the bevel was maybe 1 mm short of the edge making it a very safe knife.  I have a inherited WWI bayonet that is similarly cut safe.

With a 25 cm (10") blade width it's too much grinding for my diamond stone, I looked for a grinding solution on the internet.

Tuoh proposes to flatten the back with a belt sander,  luckily the back is not the problem. Then to add a pivot nail to the tool rest and to grind a regular bevel. The angled position of the drawknife is to stay clear of the motor.  By lack of a bench grinder I tried with my 1" belt sander, but with a support going between 90° and 45°  it's not easy to emulate.

Peter Galbert grinds using a fine tunable jig set on a flat surface.

That looks good enough for this time.  Although I think that with his setup it's possible to start grinding at 25° on one side of the blade and to finish at 35° on the other.  My implementation is ... simplified.

I finished the job on a diamond stone and added a wooden blade guard grooved with my biscuit jointer. It's all OK,  it cuts thick and thin and making sliding cuts from one side of the blade to  the other is something new for me.  The bad news is that that I also discovered I 'need' a real belt sander.

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