Show your work! Uchigumori and co...

Kitchen Knife Forums

Help Support Kitchen Knife Forums:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Watetsu, as I understand it, is just soft iron, not even cast iron? Wrought iron not made anymore in Japan? Dang, my porch rails and mailbox are worth a fortune.

Maybe, but the whole country is full of soft iron I believe, just like every modern country.

Swedish steel? I offered to split a WW2 tank made with it with a friend, but he declined. I can’t imagine why.
Watetsu means Japanese iron but it generally refers to the iron that is produced as the byproduct of making tamahagne I think. Because they don’t make tamahagne much anymore there is no Watetsu. It is being reclaimed from nails and hinges etc….

Railings and such are referred to as wrought iron and sometimes are but more generally are mild steel. Wrought iron is not commercially produced in high quantity anymore either I think…
 
Last edited:
Took my damascus Yanick to the uchigumori today and cleaned the patina off. Also decided to mirror the spine as I had some time to kill and was enjoying how meditative and relaxing knife maintenance is. Started at 400 grit paper and progressed through about 15 grits to 12,000. Then finished it with some flitz and a buffing wheel on my dremel.

Not gonna pretend this is world class work, but I had a fun couple hours.

View attachment 255068View attachment 255069View attachment 255070
Looking good!
 
Watetsu is more like a very mild wrought iron and tends to have waves in it as it’s primary characteristic and maybe very little sesame if at all

Rentetsu is more of what we refer to as wrought iron and has plentiful large amounts of slag

Wrought iron is not as widely available in Japan as it is in the USA and Europe. In Japan rentetsu and watetsu are becoming very scarce to nonexistent
 
Decided to withdraw my Indonesian Mazaki from BST and try my hand on my first stone polish. It's a not bad attempt I'd say

IMG_001.jpeg
 

Attachments

  • IMG_002.MOV
    9.7 MB
I understand the purpose and attraction to watetsu, wrought iron/soft iron. But I kind of hate it.

Why?

I have 270mm Mizuno Tanrenjo gyuto, clad in watetsu/soft iron.

This knife is fairly thick these days, something like 3.3mm above the spine. The cladding is thin. It seems to be basically a honyaki knife with a veneer of soft iron that doesn’t add any function, just for appearance.

It will rust while you’re using it. The recommended solution is to keep a wet/damp folded towel to wipe the cladding off when you’re using it, to prevent food staining. I’ve thought about removing the watetsu but it would pretty much destroy the value of the knife.

I don’t get it. Is there some reason that one would use a knife like this versus any of the alternatives?
I would be really interested in seeing this as well.
 
Wrought iron not made anymore in Japan? Dang, my porch rails and mailbox are worth a fortune.

Maybe, but the whole country is full of soft iron I believe, just like every modern country.

Swedish steel? I offered to split a WW2 tank made with it with a friend, but he declined. I can’t imagine why.
The classic progression begins with ploughshares. Tanks come later. 😏
 
Back in May I bought a Y Tanaka KU iron clad AS 240 from Zahocho.

When it arrived, things were pretty awful - super concave grind, super thick behind the edge despite the concavity, and sharp edges everywhere.

@jedy617 probably doesn’t remember his fondly.

I’m a relative newb to big geometry and polishing projects, so whilst I was okay putting some work into it, I didn’t want to ruin my relatively expensive new Tanaka.

I took it to Kataba in London to take most of the concavity out, with instructions to raise the shinogi if needed in order to maintain as much height as possible.

This is how I got it back - the height was mostly retained, concavity mostly removed, and some f****** big belt sander scratches.



There were still some low spots, so I did a full progression from a Morihei 500 -> JNS 1k -> JNS red Aoto -> Uchigumori -> Narutaki to work most of them out and get a reasonable polish.

Probably took me about 15 hours in total, mostly because I’d rediscover some stubborn remaining scratches and low spots when at the high grits and have to move down to the 500 again.

This is how it looks now - lots to refine at the heel and tip, some stray scratches and some low spots with stubborn belt scratches still present, but it’s good enough to put to use without removing even more material. I can tidy up in later thinning sessions when needed.



I had loads of advice and tips from people here. Thanks KKF, and a particular shout out to @deltaplex for letting me bounce ideas off him and making sure I didn’t ruin my knife.

Here are some shots of the WIP with some macro details and a choil shot:

 
Last edited:
Back in May I bought a Y Tanaka KU iron clad AS 240 from Zahocho.

When it arrived, things were pretty awful - super concave grind, super thick behind the edge despite the concavity, and sharp edges everywhere.

@jedy617 probably doesn’t remember his fondly.

I’m a relative newb to big geometry and polishing projects, so whilst I was okay putting some work into it, I didn’t want to ruin my relatively expensive new Tanaka.

I took it to Kataba in London to take most of the concavity out, with instructions to raise the shinogi if needed in order to maintain as much height as possible.

This is how I got it back - the height was mostly retained, concavity mostly removed, and some f****** big belt sander scratches.



There were still some low spots, so I did a full progression from a Morihei 500 -> JNS 1k -> JNS red Aoto -> Uchigumori -> Narutaki to work most of them out and get a reasonable polish.

Probably took me about 15 hours in total, mostly because I’d rediscover some stubborn remaining scratches and low spots when at the high grits and have to move down to the 500 again.

This is how it looks now - lots to refine at the heel and tip, some stray scratches and some low spots with stubborn belt scratches still present, but it’s good enough to put to use without removing even more material. I can tidy up in later thinning sessions when needed.



I had loads of advice and tips from people here. Thanks KKF, and a particular shout out to @deltaplex for letting me bounce ideas off him and making sure I didn’t ruin my knife.

Here are some shots of the WIP with some macro details and a choil shot:


nice job!
 
This is my best effort so far, but I’m getting an obvious line at the top of the convex before the flat. Do I just let up on pressure there? It’s basically a high spot along the top of the primary bevel.

PS cutting board is dirty because I’m in the middle of dinner prep

IMG_1182.jpeg
 
Early stages of a fun project I’ve been looking forward to with this Wakui WH. Seems like a great cavas to have some fun with.

About 10 min on the SP220. Bevels look really nice…no major low spots. Core steel feels awesome by the way. Super toothy.

@kpham12 I think you we’re curious about the grinds on these. I decided to make it my project knife.





 
Last edited:
Early stages of a fun project I’ve been looking forward to with this Wakui WH. Seems like a great cavas to have some fun with.

About 10 min on the SP220. Bevels look really nice…no major low spots. Core steel feels awesome by the way. Super toothy.

@kpham12 I think you we’re curious about the grinds on these. I decided to make it my project knife.


View attachment 257071


View attachment 257079
Ugh so jealous, I really want to play with one of these.

Whats the plan for it?
 
Ugh so jealous, I really want to play with one of these.

Whats the plan for it?
Work on my technique mainly. Get the bevels ready for stonework and take it down to almost a 0 (?) grind. Should be a demon cutter at that point. Then blend with sandpaper and full kasumi. Should live a long healthy life of cutting
 
Early stages of a fun project I’ve been looking forward to with this Wakui WH. Seems like a great cavas to have some fun with.

About 10 min on the SP220. Bevels look really nice…no major low spots. Core steel feels awesome by the way. Super toothy.

@kpham12 I think you we’re curious about the grinds on these. I decided to make it my project knife.


View attachment 257071


View attachment 257079
Here was the scratch pattern on mine during initial thinning. Glad to see how consistent they are from knife to knife. Super even with no low spots. Very well crafted.
1690151644408.jpeg

1690151659668.jpeg


And turned out a great cutter!
 
IMG_2292.jpeg


My first ever natural stone finished bevel. Didn’t finish with powder/mud on micromesh, as I wanted to learn the properties of my Umajiyama the hard way.

Morehei progression from 500-1000-4000, 6000ish Arashiyama, and then the Umajiyama.

Many hours later, and I have enormous respect and awe for those of you getting scratch-free finishes with high constrast and/or mirror core steels on this thread.
 
Not perfect but some quality of life improvements on this iron clad Watoyama. Spine and choil smoothed and polished, bevels fully evened out and left at a soft shoubu finish. Really liking soft shoubu tomae for leaving something aesthetically pleasing and not fussy to deal with.
 

Latest posts

Back
Top