Marc Dixon 255mm W2 'Tall' Gyuto

Thought you guys might like another 'WIP' type thread...and since this is the first 'tall' gyuto I'm doing, I thought it was a good candidate.

Back story:

A bit over year and a half ago, when I first started doing chef's knives...a member of the old KKF forums named Marc Dixon contacted me about a knife. He was among the first, and his praise for my work and high hopes for my progress were very, very kind in my eyes. I was early in my learning curve (which NEVER stops btw lol), and the feeling of someone showing that kind of interest was very nice indeed. What he wanted, was a 'tall' gyuto. 55mm or taller on the heel, and around 250mm long. The pattern wasn't relevant...other than that he loved the 'wild' look it gave the knives. We quickly came to an agreement on price (nearly HALF my current prices!), and work was scheduled to progress within a month or so. Anyhow, things happened...his finances and my time to dedicate to my work, and when his turn came up months later, he regretfully had to decline. I told him that I very much appreciated his enthusiasm and initial interest, and that if he ever wanted to return to the project I would gladly honor the agreed on pricing.

Fast forward to a couple months ago. Marc contacted me and told me he had worked things around and would VERY much love to move forward on the project. He asked me about current pricing (which I was having none of lol), and I told him that our agreement was for the pricing at the time, not my current prices. Again we quickly got into the details:

250mm edge +/-
55mm heel +/-
Larger than average handle (he has really big hands apparently lol)
Half round handle

Outside of that, my aesthetic preferences were free to execute as I pleased.

This is what I came up with:


Forged, profiled, and pre-ground.



Currently, the blade is sitting at almost 270mm long, and 57mm on the heel. The extra length and height were to combat warpage and/or possible issues with the heat treat. That said, it survived (although it warped pretty badly lol), so I will be free to shape the end profile as I please.


The black lines indicate where the apex of the two largest warps are...one to the left and one to the right. The blade almost through hardened...with whorls and spots of soft steel mixed in all over...so straightening it will be even more problematic. 64-65HRC W2 isn't exactly what you'd call tractable when trying to make it deform lol.


This is my tempering setup. The thermocouple ensures that I keep things at the proper heat, while the blade sits inside a muffle to keep air movement minimized around the blade. I ONLY straighten at tempering heat...in this case 400°F to 430°F.


As you can see, fully hardened W2 is no joke. I personally have never seen greater than 68HRC...but even still, that's nothing to laugh at. At my preferred tempering heat I consistently got 65HRC, with some blades coming in at 64HRC.


When straightening blades this hard...it's best to start out slow. I temper for an hour at 400°F, then begin my process. Slight bends, quench the blade in the vise...return to the oven...rinse and repeat, increasing the amount of bend each time. This takes HOURS...sometimes days. In the case of this blade I've been at it for two days. Believe me though, two days taken straightening, is far better than a snapped blade.



This is how the blade looked after three cycles today. As you can see, most of the bend has been removed from the heel warp (it was previously 3mm high). The tip however, still feels that 425°F and 30° bends are hilarious. Time to ramp up my efforts.



The blade is currently sitting in the vise like this while I go to dinner lol. It sat with a slightly less acute bend overnight last night. When I get home this evening, I'll be using the hammer and dished out stump to beat it into submission.

More on that later!

 

I'm constantly amazed at the amount of work put in to these knives. Not only by you but everyone here.

 

I can't wait to see this "dished out stump" process.

 

It's wonderful to me as a maker to see you guys appreciating this, lol. Honestly, the fact that I won't make through hardened blades is most of the reason I go through this though. It's either leave them crazy thick and get spotty hardening and go through belts, or make them reasonably thin and deal with warpage. There's very little in between!

 

Basically...it's a stump, with a dip in the face. Heat blade to tempering temperature, place apex of warp over low spot on stump, proceed to whale away (mostly on the spine side of the flat...the edge side will follow suit) with a 2lb deadblow. If THAT doesn't work...pick up the 4lb forging hammer, and repeat.

Remember, this is pretty much a fully martensitic blade...meaning, it's freakin hard.

 

WoW! Marc is trouble, isn't he?

 

Maybe a little lol...but nothing I can't handle .

 

Straightening with a dished out stump:





And the results. Compared to above...it's a pretty decent difference. Enough that I could get the blade on the grinder for a few light passes...then do some diagonal sanding with 120 grit to check out the hamon. Some things in life just need beat into submission it seems.



Here I've gone and highlighted the line of the hamon...and filled in the soft steel with blue stripes. Needless to say...that heel will NOT work (unless you don't care about edge holding or sharpness for the first 2cm lol).



BUT!! This is why I always make my blades a few cm longer and higher than necessary. You can see the new heel marked out...which puts this blade right at 249mm long, and 55mm high. The only thing now though, is that I HAVE to get the tip perfectly straight. In all honesty though...I wish I could have kept that portion of the heel. If the hamon had been just ONE cm high in that area, we'd have taken the extra length off the tip. I just love when there's holes of hard steel mixed into the soft and vice versa!!

Oh...and if you'll notice my assistant sweeping up? He and his older brother do house chores in competition with each other to be able to do chores out in the shop!!

Life is good!

 

This thread is awesome, but I REALLY like the last pictures of adjusting the heel to avoid soft steel at the edge. Smart....

 

Thanks brother!

If I didn't build extra into my blades in each dimension...a number of them wouldn't have made it. Sometimes there's a tiny bubble of soft steel in the middle of the edge. No clue why, or where...it just happens. Having a taller than intended blade allows me to adjust that. Marc didn't want a 270mm blade...but by making him one, I could adjust the length perfect in dimension to his preferences...while giving myself a cushion for just this type of occurrence. If everything turned out perfectly (yeah...right lol...these things literally try to rip themselves in two in the quench...SOMETHING always happens!!)...I'd have given him his choice of length from his ordered length, to the actual length, for the same price.

Now I'm back out into the shop to try to straighten the tip that last little bit...lol. NOT going to be fun!

 

Well, it finally cracked lol. I got agressive with what I thought was going to be the last cycle in the vise...and it snapped on the spine, about 3" in front of the heel...down about 1/2" into the blade.

Such is life.

But, I'm going to offer Marc a small and large utility from the pieces at the same price per mm lol. Sort of poetic justice!!

Can't beat that with a stick .

I'll be updating here when I start the next attempt. For now...out of this batch of forged blades, I have a 265mm gyuto to do for @apathetic, a 300mm suji for @Dinsdale, a 290mm suji for a gentleman on FaceBook, and a 155mm petty for another gentleman on FaceBook. This isn't counting finishing Robert's ko-gyuto, the passaround, and a 150mm petty for a friend that apprentices at Rob Thomas Damascus in Vegas. Those three just need finish polished and handled though, so I can do the work in between heat treating the other knives.

I'll start Marc's next attempt on the next batch of forged blades .

Oh, and I'll get pictures of the crack and my intended saves tomorrow.

 

Looks like there MIGHT be a 150mm petty I can save out of the nose. The rest might be forgablr into something useful...but I doubt it.



Annoying!

Anyhow...more to come later.

 

Sorry to hear that brother , having just broken a gyuto during straightening I know how ya feel

 

Stop breaking gyutos guys! You are killing me. There's a huge shortage of good knives in the world, you know, so please let it be the last one broken.
Cris. I've got a good idea. A really good idea this time. Duct tape should help fixing that tiny crack on the spine. There's nothing in the world a good duct tape can't fix (except politics).








p.s. sorry to hear about that crack

 

Oh no. That sucks man

 

More often than not we just see the finished product. Guys like me see it and think "ooo shiny!" having not really known what went in to creating the knife.
I love these WIP threads because it gives you a sense of the labor involved and the skill required. To me it makes the finished product that much better.

Keep it up!

 

+ one :like

 

Thanks guys.

I'm going to take a look at it today and see if I can save a petty out of the tip. Might be cool for Marc to have lol. If so I'll have to carefully forge the tang longer...which is tricky without ruining the heat treat, but I'm pretty sure I'm capable .

Anyhow, going to heat treat that 270 gyuto today, as well as (hopefully) at least one of the suji. My new replacement temper oven is 11" square of internal space, so I can get 15" inside on a diagonal, barely...which pretty much amounts to 270mm of edge (10.6"). Probably going to have to use the home oven for tempering on the suji. It kind of sucks because my old tempering setup was big enough to do 300mm...barely lol.

 

Honestly, I love making them. I used to do one on almost every knife lol...but figured you guys were getting bored of it. I still document all of my knives with pictures (usually they go up on my facebook page in specific galleries)...but I don't always do the WIP threads on them. Anymore I've just been posting pictures here and there on my 'What's On My Bench?' thread.

Do you guys want more? I'm going to be brine quenching a W2 o-tanto/ko-wakizashi here soon. That might be fun for you guys to see lol.

 

I love the WIP's Cris. Next best thing to being there. They are eye opening. Thanks .