Gimmick sharpener?

[Guy McVer]

I know this is not what this thread is talking about but those results are going somehow against ''common wisdom'' about simple steels and edge retention.
If I remember correctly this 'one dollar knife' in the video measured 51HRc and I doubt it's full of vanadium or other carbides but the knife stil managed to cut paper after ½ an hour of cutting spruce or pine (or whatever) wood. Amazing.
I believe Outdoors55 didn't faked the video so what's the catch? How come such simple and soft steel can have so good edge retention?

Repeat after me: angle, angle angle.

If I strike a cutting board with my edge at a 90 degree angle (for example if I am chopping straight down really hard), then I will damage the apex a lot more easily than if I were to carve into a piece of wood at a 10 degree angle. If I profile my edge at 20 degrees per side, then it will be less fragile to impacts against the cutting board than if I profile it at 10 degrees per side (but the cutting performance will also suffer because you are using a wider wedge to separate your food into pieces). If I create a scratch pattern roughly parallel to the edge (0 or 180 degrees), then it will be way more fragile at the apex than if I create a scratch pattern at 45 degrees to the edge.

Repeat again: angle, angle, angle.

That last part is covered extensively in the video. He puts a lot of emphasis on the angle of the scratch pattern. Maybe a little too much, but it was still an excellent point to make (no pun intended).

I think if you were to actually use that knife to chop food, then it would probably not last as long as it did against the piece of wood that he was carving. This is because you would be repeatedly hitting the edge straight down into the cutting board at a 90 degree angle. Knives meant for food prep are generally thinner and have edges which are steeper (thinner wedge), which makes them more fragile. This is where the steel becomes more important. Softer steels have noticeably poorer edge retention in this situation, because you are striking the edge straight on, over and over again.

Of course it would also be affected by how you cut up your food. If you use more of a chopping motion, it will probably wear the apex quicker than if you were to use more of a gentle rocking motion.

I hope all of that makes sense. I tried to be as clear as possible.

Oh, the angle of the wood fibers should also have an effect. It's a lot easier to separate the fibers if you aren't going against the grain. This can also have a significant effect on slicing paper. The paper itself can have a grain to it and you'll get better or worse cutting performance if you go with the grain or against it.

 

[TheOne45]

I think you missed my point.

 

[Guy McVer]

I think you missed my point.

Okay, cool. Thanks.

 

[Vlade]

Repeat after me: angle, angle angle.

If I strike a cutting board with my edge at a 90 degree angle (for example if I am chopping straight down really hard), then I will damage the apex a lot more easily than if I were to carve into a piece of wood at a 10 degree angle. If I profile my edge at 20 degrees per side, then it will be less fragile to impacts against the cutting board than if I profile it at 10 degrees per side (but the cutting performance will also suffer because you are using a wider wedge to separate your food into pieces). If I create a scratch pattern roughly parallel to the edge (0 or 180 degrees), then it will be way more fragile at the apex than if I create a scratch pattern at 45 degrees to the edge.

Repeat again: angle, angle, angle.

That last part is covered extensively in the video. He puts a lot of emphasis on the angle of the scratch pattern. Maybe a little too much, but it was still an excellent point to make (no pun intended).

I think if you were to actually use that knife to chop food, then it would probably not last as long as it did against the piece of wood that he was carving. This is because you would be repeatedly hitting the edge straight down into the cutting board at a 90 degree angle. Knives meant for food prep are generally thinner and have edges which are steeper (thinner wedge), which makes them more fragile. This is where the steel becomes more important. Softer steels have noticeably poorer edge retention in this situation, because you are striking the edge straight on, over and over again.

Of course it would also be affected by how you cut up your food. If you use more of a chopping motion, it will probably wear the apex quicker than if you were to use more of a gentle rocking motion.

I hope all of that makes sense. I tried to be as clear as possible.

Oh, the angle of the wood fibers should also have an effect. It's a lot easier to separate the fibers if you aren't going against the grain. This can also have a significant effect on slicing paper. The paper itself can have a grain to it and you'll get better or worse cutting performance if you go with the grain or against it.

Regardless what knife I have, eventually all of them end up at 20°. It seems to be to my liking and the performance is very good. But I do agree with the above statement 100%

 

[TheOne45]

But I do agree with the above statement 100%

I also agree 100%.

By the way, I think Outdoors55 also wanted to say in his video that if you sharpen cheap soft $1 knife the right way with stones (and strop) the edge will hold much longer as you would think it would.
I thought this cheap knife will give up after 10 or so cuts through the wood but after 1/2 an hour it still cut paper.