robo_hippy
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There are burrs, and there are burrs. I guess several types.
One is more of a 'wire' burr. These are raised from grinding more with the standard wheels. Very weak, and tend to break off with even minimal use. They are weaker of you sharpen upside down.
Another is the CBN wheel burr. I have no idea why, but this burr is very strong, and I use it on my scrapers for roughing out bowls. It is not as refined as a burnished burr, so the cut is a little bit more coarse than one that is burnished, but is fine for about 95% of what I do. I always hone off the old burr before grinding a new one on it.
There is a honed burr. These are done after grinding. You hone the top of the scraper, then the face, and some times go back and forth a time or two to remove the grinder burr. Then, you hone the face of the bevel. This raises a very slight burr in the scraper. Better for finish shear cut/scrapes, but not so good for heavy roughing. A coarser hone (220) will raise a more sturdy burr, a fine hone will raise a more delicate burr. Personally, I consider it very similar to a CBN wheel burr, but not as strong. It is almost a burnished burr, but your burnishing tool in this case is coarse compared to the rod/burnishing tools.
Then there is the burnished burr. You grind and hone like above. I use a triangle burnishing tool for card scrapers. It takes very little effort to raise a burr even on the V 10 tools like Doug makes. For some reason the round burnishers don't do as good of a job. If your bevel angle is 70 degrees, then you want the burnisher at 75 degrees. I think this is pretty close to what the Veritas burnishing tool that you screw down to your bench top does. The problem with that (I don't have one, and haven't used one) is that turners seem to really bear down on it to turn a really heavy burr on it. You can over burnish it to the point where the burr resembles a wave that has broken and the burr is turned too far over to be good at cutting. The burnished burr is a finer edge than the grinder or honed burrs. Thing to me is that they generally are not worth the extra effort to make, and I only use them for an exceptionally difficult piece of wood. They do work better on hard dense woods, not on soft stringy woods.
robo hippy
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