[pianotech] Of Chisels

[johnparham at piano88.com]

That spark test is interesting... I'm going to go test my chisels now!

-John Parham
Hickory, NC

> -------- Original Message --------
> Subject: [pianotech] Of Chisels
> From: Les Koltvedt <t4348lk at yahoo.com>
> Date: Sun, October 10, 2010 7:51 am
> To: pianotech at ptg.org
> 
> 
> The kind of sparks given off when grinding will give you a hint at to what kind 
> of steel your dealing with. Here's one site I found describing the different 
> sparks.  http://www.capeforge.com/Spark%20testing.html
> 
> I've always heard that a sharp tool is a safe tool.  There's no better feeling 
> then pushing a  chisel that you've sharpened through some wood and it slides 
> like butter.
> 
> Les
> 
> Date: Sat, 09 Oct 2010 09:10:22 -0700
> From: <johnparham at piano88.com>
> To: pianotech at ptg.org
> Subject: Re: [pianotech] Of Chisels
> Message-ID:
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> <20101009091022.f1fd8b108a58a93f763c4cd7f53850a9.fe2cdc6be6.wbe at email03.secureserver.net>
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> 
> In following this post on sharpening chisels, I ran across two
> interesting facts on sharpening kitchen knives that may apply here as
> well:
> 
> 1. If you see sparks during the sharpening process, too much heat is
> building up.  The result is you loose the temper on the blade.
> 
> 2. The evolution from cast iron (hard, but brittle and prone to rust),
> to carbon steel (harder, but still brittle and still prone to rust), to
> stainless steel (hard, resilient and much more rust-resistant) has led
> to the development of a new kind of steel called ultra-high carbon
> steel.  This steel contains a much higher concentration of carbon,
> making it even more resilient.  More resilience means the very sharp
> metal edges are less prone to breaking off. These edges tend to last
> 5-10 times longer than traditional stainless steel edges, so the blade
> stays sharper longer.
> 
> I wonder if some of these Japanese tools use this kind of metal?
> 
> -John Parham
> Hickory, NC