sharpening gouge

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sgimbel

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Dec 23, 2008
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Location
Round Rock, Texas
I built a jig for sharpening on the grinder. I sharpened everything with the original wheel and it was a real rough grind. I got a norton medium wheel and it put a real nice smooth edge on my gouges. Went to turn some wood and they cut like a 2 x 4. No cutting at all. I touched 1 up on my belt sander and it cuts fine. Any idea what I'm doing wrong with the grinder? Suggestions?
 
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I don't know what grit "medium" is but it was a whole lot smoother than the wheel that was on the grinder. I don't know about dressing the wheel. It's flat what else needs done to it?
 
I don't know what grit "medium" is but it was a whole lot smoother than the wheel that was on the grinder. I don't know about dressing the wheel. It's flat what else needs done to it?

Well, it may be flat, and yes, the wheel itself is round, but it's probably going to be slightly off center once mounted. You need to get a diamond dresser or something like that to dress the wheels after you "install" them. It's sorta like bushings being "out of round".
This is an exaggerated example, but picture this. Take a donut and roll it across the table, it probably rolls perfectly because it is round. But put your finger in the middle and spin it around your finger. As long as your finger is smaller than the hole in the donut, which it probably is, it's going to "wobble" as it spins around your finger. Dressing the wheel will true the wheel so that the outer edges are flat as compared to the center of the mandrel bolt that it's mounted on and not the actual center of the wheel.
Does that make sense...?
Here's an image I put together that may further illustrate:
 
You can also make a sharpening jig for gouges pretty easy and cheap. You just need a chunk of wood, a bolt, a steel rod.
 
another thing to consider is, Is the wheel actually getting to the cutting edge of the gouge. IE if you have been sharpening on a belt sander, the bottom bevel of your gouge is flat. On a wheel, that bottom bevel is going to be slightly radiused. the first time you sharpen on a new wheel that radius has to be reset, and will be reset each time if you don't make some sort of measuring device that puts the butt of the tool the exact same distance from the wheel each time. If you don't have the distance the same, you can easily grind what looks like a nice smooth bevel on the tool without ever touching the actual cutting edge. Just make sure that when you sharpen, you actually see sparks coming up over the top of the gouge. You should also feel a slight "burr" or raised lip of metal on the top of the gouge inside the arc of the tool. if you don't feel that "burr" or "Feather edge" all the way across, you didn't actually sharpen the tool's whole cutting edge.

Not the only possibility, but a likely one.
 
another thing to consider is, Is the wheel actually getting to the cutting edge of the gouge. IE if you have been sharpening on a belt sander, the bottom bevel of your gouge is flat. On a wheel, that bottom bevel is going to be slightly radiused. the first time you sharpen on a new wheel that radius has to be reset, and will be reset each time if you don't make some sort of measuring device that puts the butt of the tool the exact same distance from the wheel each time. If you don't have the distance the same, you can easily grind what looks like a nice smooth bevel on the tool without ever touching the actual cutting edge. Just make sure that when you sharpen, you actually see sparks coming up over the top of the gouge. You should also feel a slight "burr" or raised lip of metal on the top of the gouge inside the arc of the tool. if you don't feel that "burr" or "Feather edge" all the way across, you didn't actually sharpen the tool's whole cutting edge.

Not the only possibility, but a likely one.

This is true. A good tip is to use a sharpie to color your bevel before sharpening. Then, once you bring your gouge into contact with the grinder, you'll see for sure where it touches... and where it doesn't.
 
I took some pictures of a simple sharpening setup for a gouge. I had a Quickgrip block to clamp down but anything that would hold the original angle while you rotate the gouge would do. I matched the angle by eye and checked the grind after each 180 degree rotation. This worked well on my gouges and parting tool (no rotation on the parting tool). I don't do this all the time so building a jig was overkill for me.

sharpen1.JPGsharpen2.jpgsharpen3.jpg
 
My jig is similiar to the pictures. I kept cutting (grinding slowly) until I had a new edge from top to bottom (underside of the gouge) and I had a little burr on the inside of the gouge. The steel in smooth with the new wheel (was very rough with the old) . Can you cut to much angle? After so many times on the belt sander I really am guessing about the angle of the grind but I started out just like the pictures above.
 
The angle on mine is 40 degrees. Be sure to remove the burr on the inside of the curve of the gouge. I use an old rounded stone to make a light pass from the edge towards the handle to finish the sharpening.
sharpen4.JPGsharpen5.JPG
 
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