Mora/scandi grind edge retention?

[BryFry]

I hear lots of praise for the humble Mora knife, and for scandi ground "bushcraft" knives in general. So considering the wonderfully offordable price, I finally decided to try one out.
I bought a carbon steel Mora Classic, and though I wasn't initially thrilled with its fit, finish, or ergos, I decided it would be fun to customize it and try it out as a whittling knife.

Here it is after sharpening, and modding. And I even tried my hand at making a crude sheath...





This is my first scandi ground knife, so sharpening was a bit of a learning experience. I've always heard that scandi's are easy, but I soon realized that you have a comparatively HUGE surface of edge material to remove, seeing as how the entire bevel is the edge. But after hours of grinding away at the factory edge, I finally brought the two bevels together to a zero point edge.
This resulted in an impressively hair popping level of sharpness, and I couldn't wait to try it out on some wood....

My first few light passes at removing some hickory shavings went really well, I thought: "This is great!" ...That is until I continued. With every pass of the knife, the performance quickly and drastically deteriorated, and within moments it was like trying to shave with a spoon.
I examined my knife and could visibly see that the edge was warped and rolled quite badly all along the cutting edge. ...!!??!!

What the heck is going on here? This can't be normal can it? I realize that the zero point scandi edge means that it is quite thin at the very edge, but with all the praise these knives and this grind gets, I expected it to still perform. I used it gently I think, barely used it at all before it became uselessly dull.

How do other fans of this knife deal with this? I'm thinking of just sharpening a secondary edge on it just so I can still get some use out of the knife, but it seems to me that this would kind of defeat the purpose of buying a scandi ground knife to begin with...?

Any thoughts?

 

[willseeyalater]

Secondary bevel on a scandi grind blade is what you usually would end up doing. Still plenty sharp and better for a working edge. The scandi grind gives you an overall thin blade which has advantages in cutting.

 

[spydercobenchmadekai]

My user Mora has a convex secondary bevel. It almost never needs sharpening, and it can baton maple without any damage. IMO, it doesn't defeat the purpose, as the Mora is still an inexpensive, fairly-hard-use fixed blade.

Very nice sheath, by the way!

 

[Mikael W]

Yes, a secondary bevel is what You need on a Mora, if cutting hickory!
I put on a convexed secondary micro bevel on almost all of my Mora's.
After some time of use and a few resharpenings, this micro convex settles and the knife has got the working edge.

From here the knife hold an awesome edge!
When cutting soft materials, You can go thin, but I find the zero edge less useful for allround works.


Regards
Mikael

 

[BryFry]

Thanks guys! Guess I'll try adding the micro edge and see how that works...

 

[Cereal_killer]

I have a 30* secondary bevel on my mora and it makes for a much longer lasting edge. I use it for all sorts of "bushcraft" chores, from wood processing, cutting down saplings for hot dog/marshmallow sticks to cooking and food prep and fishing/cleaning and it holds a working edge for a few weekend camping trips at a time without needing touched up in between.

 

[link2derek]

Nice work! And I agree with the suggestion of a secondary bevel -- I have my Edge Pro Apex set just below the yellow marker (not sure of the exact angle), and it produces an exceptionally sharp, yet durable, edge on all my MoraKniv's.... love 'em!

 

[me2]

Did you take any steps to remove a burr along the edge? Was this the first time it had been sharpened except from the factory? What did you use to resharpen it?

This behavior sounds like there was a small burr left from sharpening, or possibly there was some damage to the edge from grinding from the factory. It's tough to grind that wide a bevel, at that shallow an angle and not over heat it, unless using coolant. It's also tricky to get rid of a burr on those types of knives. I have a knife that showed the same behavior; poor edge retention with light cuts on wood. I stopped using my belt sander to sharpen it, and took care to remove any detectable burr during hand sharpening, as well as lower the edge angle to 7-8 degrees per side, and now it cuts with no trouble. Try resharpening a couple of times and see if the problem stops, or add a microbevel.

 

[Bo T]

Did you take any steps to remove a burr along the edge? Was this the first time it had been sharpened except from the factory? What did you use to resharpen it?

This behavior sounds like there was a small burr left from sharpening, or possibly there was some damage to the edge from grinding from the factory. It's tough to grind that wide a bevel, at that shallow an angle and not over heat it, unless using coolant. It's also tricky to get rid of a burr on those types of knives. I have a knife that showed the same behavior; poor edge retention with light cuts on wood. I stopped using my belt sander to sharpen it, and took care to remove any detectable burr during hand sharpening, as well as lower the edge angle to 7-8 degrees per side, and now it cuts with no trouble. Try resharpening a couple of times and see if the problem stops, or add a microbevel.

I've had a similar problem with Moras. Very sharp out of the box, but it took several sharpenings to reach the full hardness on the edge. I'm guessing that there is a little softness along the factory edge that needs to be removed before you reach the full potential of the edge.

 

[FortyTwoBlades]

I've had a similar problem with Moras. Very sharp out of the box, but it took several sharpenings to reach the full hardness on the edge. I'm guessing that there is a little softness along the factory edge that needs to be removed before you reach the full potential of the edge.

Yes. This results from the buffing they do to the blades, as well as the fact that the factory grind is actually slightly hollow.

 

[BryFry]

Did you take any steps to remove a burr along the edge? Was this the first time it had been sharpened except from the factory? What did you use to resharpen it?

This behavior sounds like there was a small burr left from sharpening, or possibly there was some damage to the edge from grinding from the factory. It's tough to grind that wide a bevel, at that shallow an angle and not over heat it, unless using coolant. It's also tricky to get rid of a burr on those types of knives. I have a knife that showed the same behavior; poor edge retention with light cuts on wood. I stopped using my belt sander to sharpen it, and took care to remove any detectable burr during hand sharpening, as well as lower the edge angle to 7-8 degrees per side, and now it cuts with no trouble. Try resharpening a couple of times and see if the problem stops, or add a microbevel.

I have a full set of large DMT stones that I used to sharpen this. I keep them very wet as I sharpen to help disapate any heat.
I did have a stubborn burr to deal with, but I am pretty confident that I got rid of it. I finished the sharpening on leather strops with 2 different stropping compounds.
Yes it was the first sharpening after the factory.

Maybe I'll try and sharpen it down some more to get past any overheating from the factory. Just sucks that it takes a LOT of work to make much progress removing matterial from that larg of a surface. haha.... I spent hours and hours sharpening it the first time!

 

[jac_solar]

My first few light passes at removing some hickory shavings went really well, I thought: "This is great!" ...That is until I continued. With every pass of the knife, the performance quickly and drastically deteriorated, and within moments it was like trying to shave with a spoon.

This sounds weird. How long had you been cutting? Not the same, but I've whittled away on a 2x4 with one of those utility knives with a replaceable utility blade for hours, and I didn't notice any loss in performance.

 

[BryFry]

This sounds weird. How long had you been cutting? Not the same, but I've whittled away on a 2x4 with one of those utility knives with a replaceable utility blade for hours, and I didn't notice any loss in performance.

Probably less than a full minute. I was trimming a little from the haft of a tomahawk handle to better fit the eye of the hawk head. I barely removed any wood. Just a few thin shavings.
I too have whittled for hours with other blades with no problems. That's why I was so surprised when this happened!

Like I said though, this is my first scandi ground blade, so I'm not completely sure what I should expect from it.

 

[Thomas Linton]

If by "Scandi" you mean no secondary bevel, there is a reason hardly any knives are made that way in the Scandinavian countries and Finland.

 

[BryFry]

If by "Scandi" you mean no secondary bevel, there is a reason hardly any knives are made that way in the Scandinavian countries and Finland.

Yes, by "scandi" I mean no secondary bevel.
I was under the impression that this type of grind was renowned for its word working prowess, and loved by many outspoken bushcrafters. Am I mistaken?

 

[evanPGH]

Yes, by "scandi" I mean no secondary bevel.
I was under the impression that this type of grind was renowned for its word working prowess, and loved by many outspoken bushcrafters. Am I mistaken?

I find zero grinds to be great slicers and medium duty/edc knvies but they're definitely not something I'd want to use cutting a hard material.

Zeros with a secondary bevel are a different story, as mentioned above but true zeros are slicers all the way IMO.

 

[Samon]

You gotta remember the steel isn't anything super modern, and although it will take a fine edge it will be soft enough to dent/bend etc when used on hard woods. I sharpened mine too fine and it made a mess of the edge, its not a fault.. Just characteristics of the steel.

I don't do secondary bevels, or anything fancy. I naturally sharpen my blades with a mild convex profile (as i sharpen in hand) and done right it lends itself well to edge strength and durability.

 

[BryFry]

I don't do secondary bevels, or anything fancy. I naturally sharpen my blades with a mild convex profile (as i sharpen in hand) and done right it lends itself well to edge strength and durability.

I've converted plenty of regular V edges to convex, but I'm having trouble picturing converting this scandi to a convex. I'm pretty sure that the top shoulder of the grind could be rounded a bit, and the very edge convexed a bit. But turning the whole edge bevel into one continuous convex I don't think would happen without grinding away a relatively huge portion of the edge. (If that makes sense?)

 

[Thomas Linton]

Yes, by "scandi" I mean no secondary bevel.
I was under the impression that this type of grind was renowned for its word working prowess, and loved by many outspoken bushcrafters. Am I mistaken?

Apparently you are based on what the makers actually produce and the professional woodworkers actually use. The world once had a reputation for being flat, but . . .

 

[BryFry]

Apparently you are based on what the makers actually produce and the professional woodworkers actually use. The world once had a reputation for being flat, but . . .

...I think you lost me there. ? haha...