How to sharpen scandinavian grinds with the Tormek.

[Marc]

Hi.
First, for those who don't know what a "scandi grind" looks like, see attached picture below.

These are knives with no secondary bevels. After many tries I could not find a satisfying technique to sharpen such knives on the Tormek T8.

To properly sharpen this kind of grind, you need to put the entire bevel flat on the stone. This works perfectly well, and sharpening is quite easy on a flat bench stone. But the grind wheel on the Tormek being round, it cannot remove steel off the whole width of the bevel. To get around this problem, I tried to grind the whole bevel by changing the height of the universal support bar, but the result is not acceptable: ugly multiple scratch patterns + the bevels are not perfectly flat as they should be.

So have i missed something. I find it strange not to be able to sharpen scandinavian grinds on a machine made in Sweden. Is there a good way to sharpen Scandi grinds on the Tormek T8?

Thank you.

[cbwx34]

Hi.
First, for those who don't know what a "scandi grind" looks like, see attached picture below.

These are knives with no secondary bevels. After many tries I could not find a satisfying technique to sharpen such knives on the Tormek T8.

To properly sharpen this kind of grind, you need to put the entire bevel flat on the stone. This works perfectly well, and sharpening is quite easy on a flat bench stone. But the grind wheel on the Tormek being round, it cannot remove steel off the whole width of the bevel. To get around this problem, I tried to grind the whole bevel by changing the height of the universal support bar, but the result is not acceptable: ugly multiple scratch patterns + the bevels are not perfectly flat as they should be.

So have i missed something. I find it strange not to be able to sharpen scandinavian grinds on a machine made in Sweden. Is there a good way to sharpen Scandi grinds on the Tormek T8?

Thank you.

You might find this thread of interest...

Edit:  Ooops wrong thread initially posted... here's the right one...
https://forum.tormek.com/index.php?topic=3239.0

In particular this post...

I guess there is some cunfusion regarding the grindings and the edges and I might be able to spread som light in this issue.
First, dont confuse ordinary "Scandi Grind" (used on 90% of our construction workers and outdoor knives) with "Scandi Grind Zero" (used on carving and whittling knives).
Ordinary Scandi Grind ALWAYS has a smal secondary bevel. In our factory we use different methods on different blades but the result is similar - to make the edge stronger, less voulnerable and get a better edge retention. This is the way we have been making knives for 126 years now so I think we can claim the right to tell what is what when it comes to our knives
This is the purpose of the leather wheel on your TORMEK grinder, like stroping, to deburr and create a sharp, strong and durable edge.

Some European, American and Asian knife manufacturers has a 1-5mm high "secondary bevel" and that is NOT Scandi Grind, even if the rest of the blade looks like it would be.

One more thing to keep in mind that often causes missunderstandings: Primary grinding = secondary bevel and secondary grinding = primary edge.
This is depending on point of view; from a production angle or from a user view.
/Thomas at MORAKNIV

My .02... if you want to sharpen it on the Tormek... going the "small secondary bevel" route, is probably the route to take.  (Small blades like some carving knives can be "zero" scandi ground on the Tormek... the overall bevel isn't that wide).

[WolfY]

Sharpening a scandi grinded knife should be same as sharpening all knifes till the point that the sharpened edge after some sharpenings will move up on the blade and you will have to regrind the blade again (same as thinning). You will probably either see it or feel it as the shoulder will make the cutting more hard and not as smooth as it used to be.
I wouldn't recommend the Tormek for regrinding the scandi grind. But if no other alternative and only on occasions then remember you will get a hollow scandi and it will tear on the stone a lot. Plus will take some time to accomplish.

Scandi grind is used on most knives that are thick (3+mm) and need to have a primeri grind that will not have a cutting resistant behind the primary edge.

[Marc]

Thanks cbwx34 and Wolfie for your replies. Things are clearer for me :

- A real scandinavian grind (zero grind) can't be properly sharpened with a Tormek.

Coming from the bushcraft world and doing wood whitling, I don't like to have a micro bevel on my scandinavian knives. A micro bevel reduces wood penetration.

Since Thomas at Morakniv talks about making a "small secondary bevel" using a leather strop, I think he refers to what I call "micro convexing the edge"and that is ok on a scandinavian knife since it does not affect wood penetration. A micro bevel is typically done with a stone by increasing the angle and is clearly visible with the naked eye.


Example of a Mora knife with a micro convex bevel: The Mora Companion.

Example of a Mora knife with a micro bevel: The Mora Bushcraft Black

It is true however that our vocabulary and interpretation of language is creating some confusion here.

[Ken S]

Before we come to any definitive conclusions about this, we should hear from Tormek Support. Right now, support and probably most of Tormek is in the middle of the traditional long summer holiday. They should be back by mid August. I think we will get a more accurate answer by waiting until then.

Ken

[WolfY]

Thanks cbwx34 and Wolfie for your replies. Things are clearer for me :

- A real scandinavian grind (zero grind) can't be properly sharpened with a Tormek.

I wouldn't jump into this conclusion that fast. If you want a "0" grind E.g around 10dgrs on each side all the way to apex, you can do it. But, you blade and edge will be weak and could brake easily. Sharpening such grind, producing a micro bevel makes the edge stronger and I don't think you would feel any difference in the usage.
Just do the micro bevel very light and easy one pass on each side.

[Jan]

In my understanding the new Multi Base MB100 and the diamond wheel would allow to sharpen the Scandi grind.

Jan

[Ken S]

Jan,

I believe you are correct. I hope Tormek will have some video coverage of the diamond wheels and the Multi Base available soon.

Ken

[AKMike]

Pardon my ignorance about different knife grinds, but how would sharpening a "Scandi" grind differ from sharpening the Dala Horse carving knives in the Tormek Friends video?

https://www.tormek.com/usa/en/about-tormek/tormek-friends/

Mike

[Ken S]

Interesting observation, Mike.

Ken

[Jan]

Mike,

The video shows standard Tormek sharpening resulting in a hollow grind.

My carving knife come from the factory with Scandi grind (which is flat) and included angle circa 30 degrees. To re-sharpen the Scandi grind you need a flat grind stone. You can use a bench stone or diamond plate but you can also use the side of a true grinding wheel.

The blade of quality wood carving knives is often made of laminated carbon steel, the core hardness is 58 to 60 HRC.

Jan

[cbwx34]

Pardon my ignorance about different knife grinds, but how would sharpening a "Scandi" grind differ from sharpening the Dala Horse carving knives in the Tormek Friends video?

https://www.tormek.com/usa/en/about-tormek/tormek-friends/

Mike

Size... in particular the width of the bevel being ground? 

[Sharpco]

Check the F.A.Q of MORA. They recommend Tormek.

[Ken S]

I think the general thinking about hollow grinding has not advanced since the days when most home workshops had smaller six inch diameter high speed grinders. These small grinders produce a pronounced hollow grind, which was considered desirable for finishing hand held with bench stones.

This is another example of high speed dry grinding thought trying to be applied to the Tormek. (my opinion).

Ken

[cbwx34]

Check the F.A.Q of MORA. They recommend Tormek.

Is this what you're referring to?

What equipment should I use for sharpening?
It all depends on what resources and equipment you've got at hand. For more advanced users a TORMEK grinder at home may be an option (they also have plenty of informative and educational videos available on YouTube). In the field more easily carried diamond sharpeners (medium/fine and extra fine) come in handy. For an extra last touch, finish with stroping the knife on the back side of a leather belt.

https://morakniv.se/en/faq/

Not exactly packed with info...  (why "advanced users"?  and no info on how...) 

Maybe the videos Tormek was going to make will be helpful... 

I did run across this short video clip of a Morakniv sharpened on a Tormek that looked promising... (unfortunately not any info on how it was done).

https://youtu.be/ZPPv4EKvjsQ