Sharpening a scraper

[Trevor Mills]

Upside down or right side up? Any opinions to the pros and cons of either method, or does it matter?
trevor

[charlie knighton]

I have always done right side up

[Michelle Rich]

yes..the burr produced needs to be on the correct side :-)

[Thom Sturgill]

I don't use the grinder burr. I am reconsidering that now that I have a CBN wheel but I have in the past removed the grinder burr, polished the top, and rolled a burr just as I would a cabinet scraper.

[Brian Ashton]

Upside down or right side up? Any opinions to the pros and cons of either method, or does it matter?
trevor

Why not try each and let us know they preform.

[Reed Gray]

Well, I use scrapers a lot. They are my primary roughing tool for bowls, and I do all of my shear scrape cuts with them. I also have had the CBN wheels for years. For sure the burr left when you sharpen on one of them is much better than the burr from a standard grinding wheels. I have always sharpened them right side up. I experimented with burnishing a burr on them as in hone off the grinder burr, then use a triangle burnishing tool to turn a burr. I can't say that I can notice any superiority on the burnished burr. Note here, some claim that it is impossible to hand burnish a burr on high speed steel. Well, I did have more trouble with a round burnishing tool, but none with a triangle burnishing tool. I haven't tried the Lee Valley/Veritas jig that you screw down to your bench top. It is possible to over burnish to the point that the burr is too big and heavy, and rolls too far up and over, kind of like a breaking wave. Now, as to the upside down vs right side up, I don't know. I did talk to Jimmy Clewes about it down in Phoenix. He prefers the upside down method. His theory is that when the wheel is dragging off the steel on the top side, you get a sharper burr. I always figured that if you have it right side up, you are almost burnishing a burr onto the cutting edge, almost like the one you get when you hone a burr on by brushing across the bevel. Jimmy had just gotten a CBN wheel, and said he would experiment. I haven't heard back from him to see what he thought. I did try the upside down method, and you get a nice burr, but I can't say that it is any better than the right side up method. I do think right side up is a bit more durable for heavy roughing.

robo hippy

[John Thorson]

An upside down approach is by intent to give you a bigger burr quicker... and a bigger burr is good because? Does a bigger burr last longer? No. Does it let you take a more aggressive cut? Maybe and that might be of use in roughing-out. Most uses of a scraper is in lighter cuts both when held flat and in a shear-scraping mode. In this mode a less-jagged, higher-quality burr makes for a better finish and a smaller burr will actually last longer. I sharpen on a CBN wheel right-side up and in a real finish cut I burnish.

[Lee Watermann]

I sharpen from the back side of the grinder. I come into the wolverine slide with my Robo Rest from the back side and the other wheel gets the gouge pocket. I changed the angle on my scrapers a few degrees less and with the wheel rotating up from the bottom I have a very sharp bur and it lasts longer and can cut finer. I tried the gouges and the wings are hideously sharp. I use scrapers a lot and they cut like never before. I won't be going back anytime soon. give it a try.

[robert baccus]

I do a quick pass upside down on a 1" belt.