some subtle information about knife sharpening with the Tormek

[Ken S]

This video features two knife experts using a Tormek. Oneof them is Thomas Ericksson, grandson of one of the founders of Morakniv.

https://youtu.be/iYsgxerFKHk?si=fDHKgjQ8N_4QRb_W

Ken

[Rossy66]

Great video, nice and calm.

[tgbto]

I was having a strong feeling of "deja vu". I think this is why :

https://forum.tormek.com/index.php/topic,5601.0.html

[Ken S]

Good point. I had forgotten about my 2024 post. The video can stand on its own merits.

Ken

[Swemek]

Isn't it surprising that he said that the grinding direction doesn't matter? I've been told that the direction against the edge gives shorter burr that's easier to remove, rather than longer burr on gets from grinding away from the edge. Maybe it's splitting hairs in the context?

I have one of theses Mora carving knifes, they are a joy to use and extremely sharp when new, way sharper than the ordinary Moras, also very easy to sharpen and maintain.

Nice video, thanks!

[tgbto]

Isn't it surprising that he said that the grinding direction doesn't matter?

In my experience, the grinding direction doesn't matter (much) in terms of final sharpness. There are some knives, mostly of very soft steel, where sharpening edge-trailing will indeed form a much longer, foil-like burr. However, these steels are so soft that the foil burr will be removed easily anyway ... and edge retention will be bad either way.

That being said, it might be hard to tell from sound and feel alone when you're done honing a foil burr. I'm not sure it takes much longer though.

I also found that grinding edge-leading with the SJ stone might give the impression that there is no burr, when there actually is a line of well-aligned plastified steel just at the edge.

Eventually, I didn't find much of a difference in terms of edge retention between edge-leading and edge-trailing.

Maybe it's splitting hairs in the context?

Or whittling hair ? I don't know if it was intentional, but nice one anyway 

[Swemek]

Isn't it surprising that he said that the grinding direction doesn't matter?

In my experience, the grinding direction doesn't matter (much) in terms of final sharpness. There are some knives, mostly of very soft steel, where sharpening edge-trailing will indeed form a much longer, foil-like burr. However, these steels are so soft that the foil burr will be removed easily anyway ... and edge retention will be bad either way.

That being said, it might be hard to tell from sound and feel alone when you're done honing a foil burr. I'm not sure it takes much longer though.

I also found that grinding edge-leading with the SJ stone might give the impression that there is no burr, when there actually is a line of well-aligned plastified steel just at the edge.

Eventually, I didn't find much of a difference in terms of edge retention between edge-leading and edge-trailing.

Maybe it's splitting hairs in the context?

Or whittling hair ? I don't know if it was intentional, but nice one anyway 

Thanks for interesting post! Yes for me as booth noob and hobbyist there are a lot of variables, like how different steel behaves in one application.

I remember when I've had my T4 for a couple of months and that I kind of saw myself as some kind of sharpening guru..

For hobbyist it's always the risk falling down that famous rabbit hole.

[Ken S]

In the ongoing grinding into or away debate, I don't hear much about freehand or guided sharpening. Freehand sharpening favors grinding away for safety. Guided sharpening can be either.

Ken

[Herman Trivilino]

I found that with a dissecting microscope I can see the size and shape of the burr. Years ago I used this method to refine my knife-sharpening skills. I was able to check whether or not a burr went along the full length of the blade. I can see the size and shape of the burr and as others have mentioned it does indeed depend on the type of steel and the grinding direction, but it doesn't matter.

Nowadays I keep a piece of an old bath towel handy and run the surface of the blade across the towel. Moving the knife away from me with the cutting edge facing towards me. The burr will catch fine threads of the towel and with good light and a magnifier I can easily see them, telling me if there's a burr all along the edge. Then of course I sharpen the other side of the edge and do the same. Now I know the knife is sharp and needs only to have the burr removed.

The knife is usually either a kitchen knife or a pocket knife and is now sharp enough for everything that do with it. I know that other techniques can get an edge sharper than that, but I'm of the opinion that that effort is just for show because as soon as the knife is used it will not be any sharper than it is with my technique. I don't have expensive knives and I've never used anything other than the SG grindstone and the honing wheel with the Tormek honing compound.

I use the same technique to sharpen tools, and modify it slightly for a lawn mower blade.

[John_B]

With my knives I have found that with very little effort I can bring the edge back on knives that have declined a bit with use. I use a fine grit (2,000 and 3,000 on one rod) and light passes to bring the edge back. Like with a whetstone it took some practice to get the angle right each time, I also find that speed does not help so I take it slow and try and maintain low pressure.

I rarely see any damage on the edge from use and I individually hand wash and dry all my knives. With this practice I am able to significantly extend the time between trips to the Tormek.