Couldn't straighten the edge of my yanagiba to save my life

I've been trying to get the shinogi and edge of my yanagiba straight.
I've spent about 2 hours on a 320 diamond plate and it's really frustrating now.

The problem is I've got all the high and low spots out, all the blade road (kireha?) is touching the stone, but the edge is curving in and out beyond my control.

I drew this red line to illustrate what I mean. What I don't get however is that when I sharpen the kireha, it touches the stone evenly and still sharpens only the concave part and worsens the problem. I only put pressure on the convex bit of the edge and still it won't grind away. So tempting to go breadknife'ing on my diamond just to grind the high concave bit off but I'm fairly sure I couldn't still sharpen it properly.

What on earth should I do? Are you experiencing similar problems?

I think one bit of my problem is that this isn't an expensive knife and the finish wasn't too good. So it needed some flattening and that's where my problems started.

I've been into proper Japanese knives for about 10 years now and I think I can do a fairly good job at getting a blade sharp, but correcting a grind is much more difficult!

Would you mind posting a picture of the knife with the edge against a cutting board?

I tried to take some pictures after honing it for quite a while on the diamond again.
Here's an omote picture edge down:

Here's an urasuki picture edge down:


It got a lot better but there still is an evident bump in the handle side 1/3 portion of the blade and consequently a very slightly concave bit where the edge will not touch the cutting board. Performance wise it's OK I think now (the concave bit was about 0.5mm when I started so the whole blade looked awful) but the bump still bugs me. No matter what I do I can't get rid of it.

This whole problem started when I tried to get rid of the high and low spots on the blade from rough grinding on the wheel. I guess that's why people should get better quality blades. I spent a few hours fixing this blade and it's still not perfect. If it came hand sharpened from the maker it would be nicer but I guess that would be a lot more expensive.

I've been buying knives in the more accessible price range but that always means you will spend time fixing the blade, then fixing the stones etc. I'll try to step up for next ones.

Long story short I still don't know how to fix an uneven edge on a single bevel knife but somehow this blade got better after a lot of work. I'll go fishing now, because after correcting the bevels and working up to a final polish the white#2 blade is now sharp as hell.

Here is one of the live streams where Jon talks about this topic.

[video=youtube;q3ur175FzmI]https://www.youtube.com/watch?v=q3ur175FzmI&list=UUpgJbCAVxzDHKaKYeuGYyOA[/video]

Thanks for the video! Found other cool ones as well. I'll look into these. I'd love a wheel like that

you must remember to use the same amount of strokes and pressure for each section of the blade

you could always grind it edge down on the stone until the edge is straight, and start the process again.... at this point it would be very difficult to even that blade out section by section.