sharpening question

[Bill Mains]

When done sharpening left wing is convex right wing concave?

[AHill]

Roughing gouge? Spindle gouge? Bowl gouge?

Are you asking what it should be or are you telling us this is what you are experiencing and want to know how to fix it? Also, from what view are you describing the curvature? When viewed from the side, the upper edge of a bowl gouge should be convex or straight. If you are saying yours is convex on one side and concave on the other, then you are probably not contacting the same part of the wheel when you are rolling the tool between sides, or the pressure you're applying to the tool when rolling it from side to side is not consistent.

[EdW]

If it's a bowl gouge, the right wing is most likely on the grinding wheel longer than the left wing. This causes more steel being removed from the right wing, leaving it with the concavity that you see.

[Bill Mains]

I'm looking at the wings of spindle gouges from the side when I see convex on left wing and concave on right wing.

[MichaelMouse]

Bill Mains said:

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I'm looking at the wings of spindle gouges from the side when I see convex on left wing and concave on right wing.

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A so-called "spindle gouge" milled from a cylindrical piece of steel? If so, as above, you're grinding a bit more on one side than the other. Flute's a bit more shallow, otherwise no difference between it and deep-flute cylindrical gouges.

I ground some of of mine way back, making two straight edges coming to a point. I use them for hollowing long grain vessels. Point enters without skating, cut peels the wood, with a bit of a downward tilt on the handle when hollowing through a smaller opening, the shavings roll down and I don't have to clear with air or a spoon too often.

http://i35.photobucket.com/albums/d160/G...3b77ab.jpg

http://i35.photobucket.com/albums/d160/G...5a28f2.jpg In controlled use, the natural taper makes a great cut, as is shown by the shavings removed. The deepest point of the cut feathers out of the wood, leaving a smooth surface behind.

To return to the original question, it is NOT a good choice having a convex grind for cross-grain plungers, just as the dual convex grind on a deep flute gouge is not a good choice for long grain.

[robo hippy]

Well, most people want either a straight edge on the wings, or slightly convex. If it is concave, you are over grinding in that area. To fix it, you need to take more off the nose, or more off the top of the wing, or some of both. A lot of concave is bad in that it makes it really difficult to cut with. If it is very slight, then you can turn till it is dull, then sharpen again and work at fixing the concave shape. John Lucas has an excellent sharpening video on You Tube that shows how to do this.

robo hippy