Tojiro? Mystery single bevel rust removal and questions

[MattPike4President]

Apologies for the poor pictures, I'm an idiot working with a scratched iPhone 7. This is a knife one of my roommates bought to slice gravlax back when he was running a brunch place. It did not work for the job intended, too heavy and unwieldy. He does not remember where he bought the knife, who made it, or what it was sold as. I'm assuming its some sort of carbon steel, and I plugged the kanji into an online translator which led me to believe it's made by Tojiro but beyond that I'm clueless. It's been neglected for a year or two now, figured I'd try and fix it up a bit.

I got rid of the rust fairly easily with a rust eraser and the obvious next step is to sharpen, but I'm inexperienced with single bevels and a bit confused by the geometry of this particular knife. My understanding is that the backside of a single bevel is generally supposed to be flat (albeit hollow ground) from heel to tip but this knife has obvious taper from both sides at the tip pulling the backside away from the rest of the blade. This is visible on the backside where the obvious ground area from factory visibly stops about two thirds of the way up the knife and in this spine shot here.

How should I sharpen the backside of this knife? Do I just lift and adjust my angle to keep the blade flat on the stone? Is there a more complicated technique I should be aware of?

 

[Greasylake]

Yes it's a Tojiro, looks like what they call a "thin bladed deba" but I would probably just call it a mioroshi deba or something similar. The ura is hollow ground and to sharpen you just lay it flat on your highest grit stone and go. Sharpening on the ura is basically only for deburring so you aren't supposed to sharpen it much. If you lay the ura flat on a stone and it doesn't make contact throughout the length of the blade then the knife is bent or warped and should be straighted, which is fairly common

TOJIRO JAPAN » Blog Archive » TOJIRO Shirogami Steel Thin Bladed Deba 210mm

 

[MattPike4President]

The ura is hollow ground and to sharpen you just lay it flat on your highest grit stone and go. Sharpening on the ura is basically only for deburring so you aren't supposed to sharpen it much. If you lay the ura flat on a stone and it doesn't make contact throughout the length of the blade then the knife is bent or warped and should be straighted, which is fairly common

That was my understanding, but this looked a lot like intentional distal taper which didn't make sense to me. Would the knife come this bent from the factory? Its barely been used, never sharpened, mostly just sat rusting on a rack for the last a long while.

 

[Fedusa]

Could it be your buddy sharpened it like a double bevel knife to make it cut like what he was used to? The scratch lines parallel to the cutting edge that disappear about halfway up makes it look that way. The ura looks mostly ground away up there.

 

[MattPike4President]

Could it be your buddy sharpened it like a double bevel knife to make it cut like what he was used to? The scratch lines parallel to the cutting edge that disappear about halfway up makes it look that way. The ura looks mostly ground away up there.

I double checked with the owner and the knife has never been sharpened on either side. It was only used a few times before being put away to rust.

 

[stringer]

I double checked with the owner and the knife has never been sharpened on either side. It was only used a few times before being put away to rust.

I believe him.

https://www. chef knives togo .com/toshmide21.html

 

[MattPike4President]

I believe him.

https://www. chef knives togo .com/toshmide21.html

That's definitely the knife, having trouble telling from the pictures if it has a similar 'taper' to the one I'm working with or if mine is just bent though