I recently got one of the 600 grit wheels from Ken Rizza at Woodturning wonders. Curiosity is dangerous. Anyway, main reason was to see what if any differences it makes with my cutting tools, mostly scrapers and gouges. Skews??? Well, maybe eventually.
I never hone my gouges. I have tried a few times, and just couldn't see or feel any difference. I tried my old Tormek, and found pretty much the same thing. I have heard all sorts of claims about edges lasting longer both from finer and coarser grits. Never could notice it. With the 600 grit CBN, pretty much the same thing. There may be a little difference, but not much.
That leaves scrapers, my go to tool. I have played around a lot with 80 and 180 grit CBN wheel burrs, and there is little difference, but maybe the 80 grit is better for heavy bowl roughing. No difference I could tell with shear scraping. I have honed burrs on my scrapers, and hand burnished burrs as well, and again, I really couldn't tell much of a difference. I have been playing around with the 600 grit burr for a bit, and there seems to be a big difference. I got almost glass smooth surfaces on some myrtle, which is a bit difficult to do with gouges or scrapers. I took a highly figured maple baseball blank that was tearing out pretty bad with my skew and roughing gouges, but I could take it down to almost glass with the shear scrape, and side by side with 80 and 180 grit burrs, it was cleaner. So, much more experimenting is needed, and perhaps some one with a zoom lens for video and still shots. The 600 grit burr does not make a good burr for heavy bowl roughing. I think mostly it clogs up before it goes dull, or there just isn't enough burr to take off heavy shavings.
This leaves the upside down burr. Some do sharpen their scrapers upside down so the wheel drags the burr off the top side. Jimmy Clewes is one. It is supposed to be sharper than standard burrs. What little playing with it I have done indicates that it is pretty sharp. I can't tell if it is sharper than standard burrs though. For sure, it isn't as good for heavy roughing. Now, I have to try it with the 600 grit wheel. My current theory is that dragging the burr off of the top side creates more of a wire type burr that easily breaks off, while when you sharpen the scraper right side up, it almost burnishes the burr onto the scraper by pushing into the wheel. More testing......
robo hippy
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