Turning with Sharp Tools - Bowl Gouges, Part 2
Friday , 05 June 2015 , 08 : 20 AM
Turning Tutorials - Turning with Sharp Tools, Bowl Gouges - Part 2

Turning with Sharp Tools - Bowl Gouges, Part 2

Last month, we began covering the sharpening of bowl gouges by taking a look at how to properly choose the front bevel angle for the tool, as shown below. This angle determines two things: how well the wood cuts in woods of differing hardness and the ability to cut different shapes while allowing the heel of the bevel to remain in contact with the wood at all times.

This month, we'll be concluding by explaining the different types of grinds which can be done along the sides of the tool, also known as the "wings".

 

Traditional Grinds

The traditional grind for bowl and spindle gouges has the wings tilted back just slightly, and looks much like the photo below:

 

Pros:

  • Works well for removing large amounts of material
  • Works well for forming tenons
  • The tool can be rotated from side to side without changing the surface area of the cutting edge which is contact with the wood. Being able to use any portion of the cutting edge allows you to rotate the tool to use a sharper portion should part of the tool begin to get dull.

Cons:

  • Limits the usage of the tool for purposes other than heavy roughing cuts
  • Does not allow the tool to be used for fine shearing cuts
  • Does not work well for cutting small details. Very difficult to get into tight spaces

Fingernail (Transition) Grinds

The fingernail grind (also known as a transition grind) has the wings tilted back more heavily than the traditional grind, and looks like this:

Pros:

  • This is a great general purpose grind, effective in many situations
  • When rotated from side to side, the surface area of the cutting edge that is in contact with the wood changes slightly. The more pointed tip presents a small surface area of the cutting edge, allowing for fine, detailed cuts. The side "wings" present a larger surface area of the cutting edge, allowing for heavier cuts when removing a lot of material

Cons:

  • More difficult to sharpen than the straight, traditional grind
  • Shearing cuts can be done with the side of the tool, but does not perform as well as the Irish grind shown below

Irish Grind

The Irish grind, shown below, has the wings tilted back more heavily than the other styles of grinds. The "wings" are typically ground back to double the width of the tool.

Pros:

  • Very useful in a wide variety of situations
  • Excellent for cutting finer details.
  • Excellent for shearing cuts and cleaning up torn grain
  • When rotated from side to side, the surface area of the cutting edge varies widely. The pointed tip presents a very small surface area of the cutting edge, allowing for fine, detailed cuts. Moving towards the side edges of the tool can allow the surface area of the cutting edge to vary widely, which allows you to adjust to a variety of situations.

Cons:

  • More difficult to sharpen than the straight, traditional grind
  • More difficult to control, making it a poor choice for beginners
  • Less effective for removing large amounts of material, as you may be limited to using a small section of the cutting edge of the tool . Additional sharpening may be required to complete some projects.

 

 

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