Replies

1. 
   CharlieD | Nov 18, 2004 11:38am | #1

   I've seen slipstones designed for that purpose; seems like that would be the way..?

   Charlie

   I tell you, we are here to fart around, and don't let anybody tell you different. --K Vonnegut
2. 
   joinerswork | Nov 18, 2004 05:51pm | #2

   My preference, and I'm sure others will have their own, is to grind the edge so that the point of the V is behind a line dropped perpendicular from the top side of the chisel.  In use, this means that the wood fibers are severed at the surface,  just before the chip is wedged upward from the bottom of the cut.

   Hone the outside faces of the cutting edges with the flat side of a slipstone, or on a benchstone, and work the inside with a knife edged slip, rocking it back and forth.  The inside corner of the vee is really a small radius, and the outside is a sharp corner.  This results in a little hook or point that projects out from the bottom of the vee.  I ignore this, in use it doesn't cause a problem, it just looks funny and out of place.  Some people dub it off by rounding the outside edge at the bottom, but I prefer a sharp corner to be left in the work by the chisel.

   As with many skills, the best way to learn a subject, is by teaching it!

   Regards,

   Ray

3. 
   LeeGrindinger | Nov 18, 2004 10:03pm | #3

   It's no secret, it's just tough.

   The V-tool is the one tool I get asked most often to sharpen for people. What makes it a tough one to sharpen is that the secondary bevel must be honed flat, not rounded. The planes of the secondary bevels (bezels) must be nearly identical otherwise one side is cutting, the other is unable to contact the wood with the cutting edge.

   When you hone, hone the secondary bevel dead flat and hone the other face at the same angle as the first.

   I've seen so many V-tools that are incredibly sharp with respect to the individual sides but utterly useless as a V-tool.

   The secondary bevels must be flat (dead flat) for both edges to contact the workpiece. Any roundness will defeat this. (Did I say this? Yeah, I'm just repeating because it's the key to sharpening a V-tool.)

   I hone a bevel on the inside as well, it relieves pressure on the cutting edge and curls the chip away from the tool making it cut more easily and more deeply. A sharp angled slip is used for this.

   Lee

1. 
   jazzdogg | Nov 19, 2004 08:45am | #4

   Lee,

   Not a criticism, but the people most likely to have the greatest challenges sharpening a parting tool ("V-tool") may not be able to visualize what a secondary bevel looks like, or may not be familiar with the term.

   Any chance you could post a helpful graphic?

    -Jazzdogg-

   Whether you think you can, or you think you can't, you're right.

1. 
   LeeGrindinger | Nov 19, 2004 06:00pm | #5

   Sure, here we go...

    

   The drawing represents the cutting edge of nearly all carving tools, gouges, v-tools and skews.  There are specialized tools which are not given the bezel on the side opposite the primary grind but these are speciality tools, not for general carving.  These rules apply to the respective faces of the v-tool as well, there are just two faces to deal with.

    

   The top drawing is a tool from the factory.  The grind is there and it may be a nicely polished surface and very sharp but at this stage it's nothing but a paring tool.  Paring is done when there is no secondary bevel or bezel.  The chip is leveraged from the workpiece as the cut is made, like whittling.  Small chips are the best a paring tool can do well.  What differentiates a properly sharpened carving tool from a paring tool are the secondary bevels also known as bezels and microbevels.  These bevels allow the tool to cut deeply, endure far more stress and be more controllable than a paring tool.

    

   The bevel honed into the primary grind is done with a fine stone.  I use ceramics but there are many good choices out there.  The angle for the secondary bevel is found by rocking the tool to find the plane of the primary grind, then simply raise the handle a couple of degrees and hone away.  A wire edge will form on the face not being honed, this is an indicator that good things are happening.

    

   A bezel is then honed into the inside of the gouges, the inside of v-tools and the opposite side of straight edges such as skews.  It does not have to be a long bevel but it needs to be there.  This bezel acts as a chipbreaker and it makes it possible to use both faces of the tool which is impossible without a bezel inside.

    

   The point between the primary grind and the secondary bevel is the point the tool rides upon to control the depth of cut.  On the opposite face it's the point between the untouched face and the bezel you put there.  In both instances the angle of the honed face is the angle of attack for the carving tool.

    

   The trick for v-tools is getting both cutting edges in contact with the workpiece at the same time.  Any roundness in the honed faces will prevent one edge from contacting the workpiece.  Although both faces can be sharp enough to shave a fly's arse the tool is worthless if both edges cannot contact the worpiece without raising the handle to vertical.

    

   Lee

    

    

   
1. 
   jazzdogg | Nov 23, 2004 03:01am | #6

   Lee,

   Thanks for posting the drawing and expanded explanation. I printed it out and plan to share it with my fellow students in the carving class I'm taking this semester.

   Sharpening the parting tool has been challenging, but when I finally got it properly sharpened, it made a world of difference. I guess the parting tool is to carvers what a skew is to turners - a challenge to master, but a valuable part of the arsenal with a little practice!

    -Jazzdogg-

   Whether you think you can, or you think you can't, you're right.