About

Kitchen Knife V1

Project: November 2020

Writeup: March 2021

Not bad, right?

This was the first knife I could say I was properly happy with. I think everything came together nicely. Oooooh buddy that hamon...

So, we've got:

*I think. It was just from the pile.

The shape was inspired by (read: stolen from) a Yoshimi Kato petty with a western-style handle which I loved. It was interesting to see a small, elegant blade shape done with a full tang and such a chunky bolster. So I spent a while studying photographs to put together a scale outline which I could then print.

The blade was then inelegantly hacked out of a piece of 1095 and massaged into shape with my (homemade) belt grinder and various files:

Today on Episode 487 of "Things you shouldn't do on carpet"...

It's not really the ideal tool, but I got there in the end. Learning as I go here.

Took it to 400 grit before hardening. I've found this to be perfectly fine for my process: I've never gotten too much scale for whatever reason. The blade is wrapped in wire and the spine smeared with exhaust sealant (just conveniently-packaged and readily-available high-temperature clay).

Clay on the spine: slower cooling during quench: softer steel. Blade cools fast for max hardness.

Then I heat to critical temperature in my (also homemade and equally jank) propane forge and quench in Parks 50. Pull all the wire and clay off here, then go to temper. While doing this (ie. at its hardest, MOST DELICATE STAGE) I then proceed to drop the blade on my tiled kitchen floor. Luckily it was fine but I sure did swear a lot. Two 2-hour tempering cycles at ~215°C*, then slowly back to 400 grit, taking edge down to final thickness (keep it cool keep it cool keep it cool). I haven't found it worth it going to any higher grits when you're going to etch: 400 gives a nice satin.

*Had to dial this in with some test pieces. It's like 230°C on the oven dial

First etch was promising, but the heat treat was bad. The hamon line was lovely but didn't make it all the way to the tip or heel - indicating an uneven heating during hardening. No choice but to go around again here. Normalise, harden, temper, 400 grit, etch. I was concerned that the edge (which was now much thinner than the first time around) would have issues with all this thermal cycling, but it turned out perfectly

Etch in ferric chloride to reveal the gorgeous, even hamon from tip to heel. So pleased. It probably had about 10 minutes in total in the etch, being softly jiggled around and brushed off every minute or so. It could probably take a bit more: need to experiment. Then slowly hand polish to really bring out the gradient. I found Brasso to be nice and gentle here.

Now you just have to put the handle scales on without covering your perfect blade in epoxy... Got there in the end.

Probably not the best wood, but I like the colour.

All in all very pleased with how it turned out. Sharpening is nerve-wracking because you're trying not to go too shallow and grind too far up the edge. But got a great edge in the end: holds up well, having been in use for a few months now. I was surprised how well the etched surface holds up. It seems to prevent the worst of the natural patina you get with carbon steel knives in the kitchen, at least on the softer, slightly darker spine. I've found 1095 very easy to work with: it's amazing what an idiot can do with a propane blowtorch and files in his spare room. but I'm probably not getting the best out of it yet! In future I'll pay more attention to the geometry from the start.

Also next time: lighten the tang. It's not obnoxiously heavy, by she's got some gravity in her. Balance point is probably supposed to be somewhere down the blade: this one feels roughly centered.