What is this weird Moiré striation on my bevel?

[mengwong]

We have here a Tojiro DP 3Layered VG10 170mm Santoku pretty much brand new, which I just put through a very light SG 2k 4kHC 8kHC sequence, plus an attempt to polish one side. The edge is fine. It cuts paper towel, it cuts standing paper, it cuts the hair off my legs. There are no chips. This is not a massive burr, this is the bevel. You can see the hamon.

But there are these weird … striations? That repeat every 4mm. They appear on both sides. Only visible at certain angles.

Is this some kind of Moiré-like interaction between factory grind and my polish? Between strokes at one angle and one grit, and strokes at another angle and another grit?

 

[ian]

My guess is that you haven’t hit all of the bevel. Maybe you were using a slightly higher sharpening angle than the bevel angle (so there’s now a microbevel at the apex), and the big bevel was originally done kind of inconsistently, like on a belt or wheel? It almost looks concave, which is a little surprising to me, but whatever. I have no idea how tojiro does their initial sharpenings. Anyway, probably it would all clear up if you just work on contacting the big bevel.

 

[HumbleHomeCook]

You just haven't ground in "your own" bevel all the way is what I would say.

 

[Mr Kooby Shemayrew]

Looks like lighting. Do you have track lights or LED’s with multiple bulbs?

On the last pic, is that light coming through some kind of slats?

 

[Benuser]

Start your sharpening at a lower angle than the final one, raise the spine only little by little. Make sure to get rid of the factory bevel with your stone, and check with a sharpie and a loupe whether the entire bevel is clean, up to the apex.

 

[inferno]

just grind more until they disappear.

take a black marker and paint the bevel. sharpen for 10 seconds. inspect.

are you hitting the whole bevel? if all the paint is gone you are.

with that being said. you might not want to keep that angle anyway.

 

[Pie]

Factory ground knives often have very uneven edge bevels and sometimes these deeper grind marks that come at even intervals.

All signs point to not enough material coming off on the coarse end of things. I’d maybe hit it with 500 grit or less to really clean out all the original scratches.