Mora edge angle?

S

skippz

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Feb 12, 2006
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Anyone have a rough (ballpark) estimation of what edge angle mora knives use? Specifically the mora bc black? I have one & have done ok freehanding it but was thinking of taking it to my sharpmaker, however I don't want to reprofile the edge & would like to keep the scandi grind & not create another bevel. This thing came scary sharp & I would love to get it back there, have the ultra fine ceramic stones on the sharpmaker already...
Any help would as always be greatly appreciated.
Thanks!!!
 
The sharpmaker angle at the 15 dps (30 deg inclusive) is like more obtuse than the Mora scandi bevel, so yes, u will likely create an additional bevel.
 
If the Moras are anything close to the scandi grind on my Helle scandi, they'll likely be much more acute than the 30° inclusive setting of the Sharpmaker. My Helle 'Dokka' model (a folder) is ~17°-19° inclusive at the edge, meaning 8.5°-9.5° per side.

You could still use the SM to sharpen it, though. As with any scandi blade, the wide bevels ARE the angle guide for sharpening; just lay the bevel flush to the rods to sharpen it, and don't worry about holding the blade vertical between the rods. If you have to remove much metal from the wide bevels to apex the edge, it'll take a very, very long time on the SM, however.


David
 
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I wanted to reply as soon as I read your question, OP, but David beat me to it and took the words right outa my mouth! The included angle of those knives is around the 17 degree mark, so holding the blade as you normally would on the SM would certainly create a new bevel. You can certainly do that with a zero ground edge, if you want to, and many do. I would keep the original geometry for sure. You can use the SM, just as David said. Lay that whole bevel flat against the sticks and go to town! May take a while on SM, tho!

Great answer, David. Of course it was, it was what I was gonna say!
 
What stones would you guys recommend using? I have a DMT diamond stone, but am hesitant to use the diamond on it, I typically use ceramics & have had good luck with those.
 
You could use the diamond plates - a waterstone or other vitreous stone might be a better choice. If you opt for the diamond plate, a bit of soapy water will help tame it a bit. Cosmetically you will see the hatching from minute shifts in angle, these can be removed easily with a strop.

Some sandpaper over a hard block would be pretty good choice too. My Moras have an inclusive around 22-23*, I find a bit of induced convex to open them up to 26 or so makes the edge a lot better for general use.
 
skippz said:
What stones would you guys recommend using? I have a DMT diamond stone, but am hesitant to use the diamond on it, I typically use ceramics & have had good luck with those.
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The wide bevels on a scandi are tailor-made for a full sheet of wet/dry sandpaper firmly-affixed over a glass or flat stone backing. With my Helle folder's (stainless laminate) blade, I initially started with a diamond hone to take it down to a true zero-grind (it had a very small microbevel when I bought it). Due to the large amount of steel that has to come off the wide bevels, it's fairly easy to clog a diamond hone this way, and the grinding will slow quite a bit. I eventually shifted to using some wet/dry paper over a granite reference plate, and that worked beautifully. The additional bonus in using the wet/dry paper is the wide grit range available, which really streamlines refining and is perfect for maintenance-sharpening as well. Also did some finish polishing on a translucent Arkansas stone (used with oil), and that worked very well on this blade.

Ceramics like the Spyderco hones can be great for finishing & touch-ups done with a feather-light touch, but they'll always be very slow for any heavy grinding tasks. The very wide bevels on a scandi will slow it even more; exponentially, in fact.


David
 
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You can lay the stones on the sharpmaker down (horizontal) next to each other, on the back of the base, and use them as like a regular ceramic stone, and sharpen your scandi the proper way, as well.
 
The answers to the edge angles are on this page

http://www.moraofsweden.se/knife-care

Always work at the same angle the blade was originally ground to, usually 23°
.....
The 3.2 mm thick blade on our Bushcraft Black is annealed slightly more to 56-58 HRC to better withstand stress on the blade when batoning. The edge angle is therefore slightly greater (~27°) to stand up to tough treatment better.

My advice is keep it flat on a stone and do not use any sort of jig
The Scandi lends itself to use directly on stones
 
Scandinavian traditional knifes have edges around 10 degrees per side of the edge.

Mora knife edges today holds around 11 degrees per side = around 22 degrees total edge. They mostly also have a micro edge in around + 2-3 degrees per side. That means that the angle on the cutting edge is around 26 - 28 degree total edge.

The micro edge is 2-3 tens of 1 mm wide.

Thomas
 
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Thanks guys... I've got wet/dry paper already, do I just dry sharpen it or should I use water/oil?
 
You will get longer life from it if used dry and cleaned often. A pink eraser or synthetic wine cork work very well.

You can use it with Windex, oil, water, soapy water and all will work well and in some instances produce a slightly finer scratch pattern at a given grit value.

For longevity and convenience I recommend using it dry, very light pressure (switch to a more coarse grit rather than apply more than a few ounces of force), and clean it often, every minute or so as it loads up with swarf.
 
skippz said:
Thanks guys... I've got wet/dry paper already, do I just dry sharpen it or should I use water/oil?
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I think I wetted the paper I used, if I recall. I often use it dry for touch-ups and light work; but with big jobs that need a lot of metal removed, using some water (or mineral oil) with the paper seems to help keep the paper from clogging too fast. Also seems to leave a cleaner scratch pattern, likely for the same reason (keeps swarf out of the way). If you do wet the paper, it's all the more important to keep the paper 'stuck' to the hard backing, because water will tend to make the paper curl up otherwise. Might be worth experimenting with it a bit, to get a feel for how it'll work for you.


David
 
Once I sharpened my scandi on stones properly (e.g. 500 Beston, 1000 and 3000 jws) and got rid of the burr as much as possible, I finish and maintain my scandi bevel on thin, hard leather with 1000 CBN. Due to some give, effectively it is about 2000 grit and gives a little more convex. I only go back to the stones if I have a chip/roll etc.
 
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