I've recently bought a (cheap) usuba knife to practice some new techniques. I've got 2 question.
Unfortunately I noticed the edge of the knife isn't straight: when the edge is placed on a flat surface some parts of the blade touch the table whereas other parts don't. This can clearly be seen in the following photo:
I guess I can just try to 'reshape' the edge (starting with a rough whetstone), but I expect this is going to be a pretty hard job. Is there a good 'standard' technique for this or does somebody has some good advice for me?
Next to this, I have another related question: when sharpening the usuba I place the entire 'blade path' (kiriba) on the whetstone when sharpening the front side. As I understood (correct me if I'm wrong), this (see cartoon below) is the way to sharpen a single bevel knife:
A problem arising from using this techniques seems to be that I introduce scratches on the 'blade path'/kiriba-part as pointed out by the red arrow in the photo below. I find these scratches unappealing, and would like to learn to sharpen a knife without scratching it in this way.
So my second questions is: can this usuba be sharpened without introducing these scratches or should these scratches be removed by polishing after sharpening? Or is this (cheap) usuba possibly just of low-quality and will these stains/scratches not appear when I sharpen an expensive usuba in the same way?
thanks in advice!