Why cant i sharpen a scandi grind?

Joined
Aug 31, 2012
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I can sharpen convex and v edges fine and i get great results. I just got a new knife and the edge aint as sharp as i would like i. So i looked up how to sharpen a scandi grind and people say it is really easy. I tried my diamond stones, strops, ceramics, and sandpaper. I go from edge that was decent to dull as a butter knife and i dont get how my technique can be that terrible on something where it pretty much guides you. I am looking for any tips because i really wanna use this knife.

Thanks.
 
Though I myself haven't sharpened a scandi grind it is possible that the grind isn't perfectly flat--rather slightly convex. And there's a chance that you're not hitting the very edge of the knife. Make sure you've formed a burr and can get a decently sharp edge at the lower grits before moving up.
 
A lot of Scandi come with a slight convex - this isn't a bad thing IMHO but making it too convex seriously degrades its cutting performance. Start grinding at the shoulder/bevel junction and work toward the cutting edge, not from edge to shoulder. Also I find that keeping good contact with my finger tips on the blade right where I'm grinding, is critical to keeping that angle nice and acute. Take extra time around the belly and into the tip - very easy to round this over a bit. Use a Sharpie, mark lines from edge to shoulder and check often so you can see exactly where you're grinding. After you do a couple, they get easier, but to do one very cleanly still requires a lot of attention - more so than a Vbevel or convex.
Take your time with the coarse stone work - there's too much surface area to make any corrections with the finer stones, so be critical and make sure you're happy before moving to a finer stone(s).
 
I have been tinkering around with scandi reprofiling and sharpening for quite some time now, including a lot discussion with BF members, with HH quite a bit. There is more to scandi sharpening than most people think, at least in my opinion. I also approach scandi completely different than thin v bevel knives. First, I use both hands alternating, meaning for the left side of the blade I use my right hand holding the angle and my left hand does the sharpening/moving/pressure. Vice versa for the right side of the blade. This gives me a much, much more uniform grind. I almost exclusively now use the Norton Crystolon stone with oil, I switch to JWS if I reach for a near mirror polish. HH washboard is perfect (with 2 sheats of paper) for refining/burnishing the edge/apex.

I now do forth and back motions, following the belly of the knife, means turning and lifting. That also has the advantage that you can see better when you are at the tip since for the most part, as soon as the final belly part/tip apex is perpendicular to the stone (my stone is 90 degree angle towards me), you are done turning the knife (unless you want to reprofile the tip). Since I actually prefer the very slight convex bevel that you get if you freehand sharpen a scandi (there is almost no way to keep a scandi bevel completely flat freehand plus, the slight convex performs better in pushcut into wood, wood shavings and feather sticks IMHO). I hold the knife quite tight in my hand which contribute to the convexity since my wrist rolls a bit (forward stroke lowers the angle, backward stroke increases it) and therefore the knife has to follow. If you want a more flat scandi, holding it loose and control the pressure with the other hand keeps the bevel flatter on the stone IMO. You can then control the bevel more by pressure points then angle holding!

Once I have established an even grind and burr of course on both sides, I cont. the same motions (for and back) but very very light until no significant burr. On scandi, if I only did edge leading strokes to remove the burr (which I do exclusively on v bevel knives though), you very likely end up with a slight micro bevel on top of the "scandi-vex". It can be done but requires particular patience :( The cont. of very light forth and back strokes ensures that I keep my "convex" motion. Now, don't get me wrong, I am talking about a very slight convex if you hold a straight rule against the scandi bevel, you can see it. As HH often mentioned, I guess about a degree or two!

Once the burr is gone and you are finished with your final stone, use a HH washboard (or a strop) for final finishing. I noticed a tremendous improvement of the apex with plain paper on the washboard, if you don't do too many strokes (edge trailing this time of course). I have also not noticed any rounding of the apex!

Sorry, this was a long rambling!
 
I typically grind each side with a 1k waterstone until a apex and burr forms then add a micro bevel with a higher grit stone.
 
Here's a pair of videos I did using compound on oak, but some good tips IMHO for doing Scandi's in general:

[video=youtube;1nxmn-aJwQY]http://www.youtube.com/watch?v=1nxmn-aJwQY[/video]

[video=youtube;gfblDsTy-FY]http://www.youtube.com/watch?v=gfblDsTy-FY[/video]
 
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