PSA - don’t lend out carbon knives: An ongoing project thread

[Pie]

I got this knife from Japan as a gift from my wife, before I had progressed past the 165mm Santoku phase. Abused appropriately, but remained in excellent condition. Recently touched it up to a 10/10 sharpness, relative to my personal sharpest. I essentially know nothing about this knife, steel, maker, nothing. All I know is it gets uncomfortably sharp.

So I lent it to a coworker who wanted to try Japanese knives. This is what came back

After the appropriate freaking out, pulled the amakusa out and went to town (carefully) gauging the grind, flatness and shinogi. As expected, plenty of unevenness on the bevel, somewhat aggressive convex, but nice soft cladding to take down. Had the standard vertical scratch finish, which is on its way out.

10 minutes of quick work

I’ve been looking for a bit of a project to give my mazaki a break and actually use the damn thing, I guess this is what the knife gods sent down.

Updates as it progresses

 

[WiriWiri]

I’d love to have heard the explanation for the state of that. I’m guessing something like:. ‘I’m really sorry Pie, but I went swimming and must have left the Santoku in my wet speedos?‘

 

[esoo]

Guessing that is what happens when you leave this for too long:

 

[ian]

Guessing that is what happens when you leave this for too long:

Ahhhh! Pizza-gate!

 

[Pie]

Seems like it’s always santokus that get treated poorly. The nakiri that was lent out was stainless, so just came back with a couple small chips. Been thinking about it all morning, might make it into a full restoration as the knife itself came pretty rough ootb.

My guess is it went into the blade guard not completely dry and rusted out over a couple weeks. Really it’s kind of my fault for not giving better instructions for knife care, but hey at least it wasn’t my denka

 

[TB_London]

It’ll buff out

 

[Pie]

Did some more thinning with SG220, got most of the original finish off but a couple low spots remain. The original idea was to completely remove all low spots, but the one at the heel is tooooo deep. The ones under the shinogi may take a bit of time.

Pleasantly surprised with how small the edge bevel is getting with the thinning

 

[TB_London]

Nice, always worth remembering you only need to do this once, from now on You’re one easy street

 

[Carl Kotte]

’sorry, I made this knife rust!’

 

[Pie]

Another ~40 minutes thinning, I had to step down to the lobster stone cuz the SG220 was taking too long and glazing. I realized just how much steel came off as the entire convex is almost gone. I wanted to clear the low spot first before changing angles and repairing the convex, but looks like I’m going to end up basically creating convexity from scratch. It’ll be another good learning experience gauging how much to take off and seeing what the Shinogi looks like. This is the first time I’m completely redoing a primary bevel, kinda excited to see how it polishes.

From a grind quality perspective, this thing’s actually not bad compared to some higher priced knives.

Pictured below - stubborn low spot above the shadow at the cladding line, and edge bevel comparison (thinned side and not thinned side) where I’m working on the low. Haven’t hit absolute zero grind yet, but it’ll be close. Out, damned spot!

 

[TB_London]

Move where you’re applying pressure with your fingers to be up towards the top of the bevel and that will blend in.
I wouldn’t try and make it flat first, start work to convex it now, and shifting where you’re applying pressure will do that for you.

 

[Pie]

Move where you’re applying pressure with your fingers to be up towards the top of the bevel and that will blend in.
I wouldn’t try and make it flat first, start work to convex it now, and shifting where you’re applying pressure will do that for you.

Thank you for the tips!

The upper part of the convex is.. pretty small now. In past thinnings I just put the pressure right under the shinogi and it was pretty easy to control. Took a short crack at it this morning, it’s kind of uncharted waters for me trying to work down the bevel from such a small “flat” at the top. Seems I may have moved the shinogi up a little bit and found some new lows to battle. Alternating hands (and therefore scratch pattern) gives me an idea of where I’m taking metal off, must remember to check often.

this might get ugly, but I’ll post up before introducing the 3rd facet and blending.

 

[Pie]

So I managed to fly through NP400, 1k and 3k without taking many pictures, too excited during the progression to take pictures. Scratches persisted through 3k, was kind of worried as I’ve never seen scratches from the 3k. Worked it until the core was almost mirror, close enough to let the jnats do the
.

I think this was somewhere in there, probably off the 1k.

From Naniwa pro 3k straight to a soft Hideriyama I have from Takeda’s collection, I absolutely love this stone. Soft enough to self slurry, fast enough to remove all 3k scratches in about 2 passes, and suuuuper smooth. So noob friendly. Vetted by Takeda, this thing is worth the price. First few passes resulted in Good contrast, little unevenness, but surprisingly easy

got stuck to the stone resulting in that one big ugly scratch but good enough to not step back and continue up.

 

[Pie]

Late update: took it to full polish on the Hideriyama - easy to polish, even easier on an even bevel, turned out dark with high contrast. Might be my preferred finish tbh

Went up to a hard suita, difficult to keep it consistent due to hardness of the stone, stayed a bit gentle near the cladding line to keep the contrast (this stone will almost mirror the cladding) - ended up with an interesting gradient that’s sort of black mirror overall.

I guess this side is finished, looks decent, low spots are gone, and the polish is not bad. This was about a week ago, and I super f’d something up - next post.

 

[captaincaed]

Came home from work to see this. So glad she's stainless.