Finished my first kitchen knife! Lessons learnt and some new methods...

[AVigil]

Oh yea lots of makers are using it. Some makers will say not to use CA glue and then many top makers ignore them and use CA glue...lol

 

[aarongough]

Oh yea lots of makers are using it. Some makers will say not to use CA glue and then many top makers ignore them and use CA glue...lol

Two of my friends recently started a company building high-end guitars, they put a big sign on their wall which I think is pretty awesome:

"One test is worth a thousand expert opinions."

I think different methods work differently for everyone, maybe because of little variables we're not even conscious of! Also everyone's definition of success is different, so it can be hard to fully share experiences. I think testing stuff for yourself is really the ultimate way through this quagmire.

"Test to destruction" has become a bit of a mantra for me

 

[Shaw Blades]

Do you grind before or after heat-treat?

After on these long thin blades.

 

[aarongough]

After on these long thin blades.

Yeah I figured that would be the case... Maybe try plate quenching and see if it helps. I also find that if I put the blades in the kiln on their spine they're less likely to warp, but I know of others who found the opposite

 

[Lu1967]

I have the same problem.May try hydraulic press after temper or try
hanging in front of a fan vertically to quench.If it's memory in the steel
i don't know if it'll help.Iv'e only done 3 blades using the plates.Very nice knife by the way.

 

[aarongough]

So I'm not sure if this would affect the warping or not, but I coated the blade in anti-scale (ATP-641) then put it in a stainless foil envelope. The envelope was left on for the quench, the whole package was just put in between the quench plates. The quench plates are quite substantial, about 7/8" thick, by 4" wide and longer than the blade.

Other thing I did was I didn't leave the blade in for the entire time the kiln was ramping up. My kiln is fairly slow to ramp to the higher temps, so I put it in once the kiln had reached 1900ºF, then it stayed in there for about 15-20 minutes while the kiln finished ramping to 1995ºF. It was laying on it's spine in the kiln, roughly in the middle, supported by the evenheat knife fixture.

 

[Shaw Blades]

That's interesting. I usually throw mine in when it's cold and let it ramp. I'll try your way. I do put them spine side down on a notched out soft firebrick stand I made.

 

[coldsteelburns]

Aaron, man I just love your threads :thumbup: I feel I can trust your knowledge due to all the extensive testing you always do including sometimes very hot temps, but always very cold (sub zero) temps. All I can add is that I really appreciate all the work you put in and openly sharing and documenting all of your experiments so neatly for everybody to read. I really feel I can trust the info you provide so thanks again for your hard work brother! Keep 'em commin!

~Paul

---

My YT Channel Lsubslimed

 

[aarongough]

That's interesting. I usually throw mine in when it's cold and let it ramp. I'll try your way. I do put them spine side down on a notched out soft firebrick stand I made.

For A2 I preheat the kiln to 1100ºF, then put the blades in and let them come up to temp during the ramp to 1775ºF. But that's pretty quick, maybe 30 mins tops. With the higher temps my kiln is slow, so I didn't want the blades in there experiencing grain growth for an hour or more while the kiln came up to temp. Not sure if it will help, but it's worth a shot!

Aaron, man I just love your threads :thumbup: I feel I can trust your knowledge due to all the extensive testing you always do including sometimes very hot temps, but always very cold (sub zero) temps. All I can add is that I really appreciate all the work you put in and openly sharing and documenting all of your experiments so neatly for everybody to read. I really feel I can trust the info you provide so thanks again for your hard work brother! Keep 'em commin!

~Paul

Thanks Paul!
I've found that it's super valuable for me to share. It helps out others, and others get the chance to help me out with things I might have missed or bring up different/better ways to do something!

 

[FTO_dude]

Hey Aaron.
I too would describe heat treated AEB-L as 'weird' and have also thought that cryo might change things.
I find my results particularly perplexing. Heat treated pre-grind, comes out of quench at 60-61 yet If i bend it with my hands, at room temperature, it will take a set. But after grinding its perfectly springy. Very fine grain in the cross section.

I look forward to testing your CA method of handle glue up. On a properly prepped joint, CA is a lot stronger than most give credit.
I use it when joining components on 'wa' handles. when the whole handle is then epoxied onto a tang its pretty much impossible to remove it without smashing the whole thing to bits.
Using it on full tangs might be an uphill battle though, customer wise.

 

[aarongough]

Hey Aaron.
I too would describe heat treated AEB-L as 'weird' and have also thought that cryo might change things.
I find my results particularly perplexing. Heat treated pre-grind, comes out of quench at 60-61 yet If i bend it with my hands, at room temperature, it will take a set. But after grinding its perfectly springy. Very fine grain in the cross section.

I look forward to testing your CA method of handle glue up. On a properly prepped joint, CA is a lot stronger than most give credit.
I use it when joining components on 'wa' handles. when the whole handle is then epoxied onto a tang its pretty much impossible to remove it without smashing the whole thing to bits.
Using it on full tangs might be an uphill battle though, customer wise.

That behaviour from AEB-L is definitely quite strange... Can't really think why that would happen. I will say that so far I definitely like A2 better, and would also prefer CPM154. That might change once I try some AEB-L with cryo, and maybe a few tweaked heat-treats.

I'm not too worried about customers objecting to the use of CA. I'll do my testing and share the results, if there are objections after that then it has to be said they're groundless.

I'll probably also do some water immersion testing. I'm satisfied that good epoxy will be fine pretty much indefinitely when exposed to moisture, not so sure about CA so it needs to be tested!

It should be said too that I only really think of the glue as a sealant in any case, the bulk of the mechanical strength in the handle is provided by the corby bolts.

 

[Tin.Man]

Aaron- As always your threads are a WEALTH of information. AEB-L behaves quite differently once above 60. Although getting it above 60 is quite a challenge. Last batch I got back from Peters, Brad said he was having a hell of a time going above 61 (my goal was 62) He nailed 61 with cryo and I mainly use A2 as well and at 61 it behaves very similar to A2 at 60+. I believe they both have very similar fine grain structure.

Weird about the stringiness, when I grind AEBL after ht its a beautiful fine VERY clean dust. Almost as clean as Elmax which has been the absolute cleanest to grind to date for me.

Love the superglue idea. As always man thank you for sharing!

 

[aarongough]

Aaron- As always your threads are a WEALTH of information. AEB-L behaves quite differently once above 60. Although getting it above 60 is quite a challenge. Last batch I got back from Peters, Brad said he was having a hell of a time going above 61 (my goal was 62) He nailed 61 with cryo and I mainly use A2 as well and at 61 it behaves very similar to A2 at 60+. I believe they both have very similar fine grain structure.

Weird about the stringiness, when I grind AEBL after ht its a beautiful fine VERY clean dust. Almost as clean as Elmax which has been the absolute cleanest to grind to date for me.

Love the superglue idea. As always man thank you for sharing!

Interesting that you get such different dust when grinding. Any idea what the heat-treatment schedule is that Brad's using for your knives?

I find the idea of AEB-L very interesting, which is why I bought some to try. Clearly my next attempt I'll have to tweak the heat-treat a bit!

 

[Don Nguyen]

Interesting progress Aaron. I can't say too much about the steel since I haven't used it yet, but I'm paying attention because AEB-L and CPM154 are my choices to experiment with in the future.

I never realized you were a heavy rocker, and not a chopper, so my previous advice on the profile might not hold Looks like you're on the right track though. I'm sure you'll figure out the edge thickness and handle geometry in no time.

 

[aarongough]

Interesting progress Aaron. I can't say too much about the steel since I haven't used it yet, but I'm paying attention because AEB-L and CPM154 are my choices to experiment with in the future.

I never realized you were a heavy rocker, and not a chopper, so my previous advice on the profile might not hold Looks like you're on the right track though. I'm sure you'll figure out the edge thickness and handle geometry in no time.

Hey Don!
I thought you were referring to my taste in music for a minute then rather than my taste in knives... I'm a heavy rocker in both aspects!

I have always used german style chef's knives, but this has never been a conscious choice, it's just what was around. I did a bunch of cooking tonight with the new knife and actually quite like the profile, the technique is a bit different but it seems fairly natural. Dicing an onion with such a thin blade was really nice. I thought it might be too thin and flexy initially but that hasn't been a problem at all so far.

I'm planning on getting a bunch of different styles of knife over the next few months to try them all out and see which I like best, should be fun!

I'll keep you in the loop regarding the steels. I'm personally a bit more excited about getting to play with CPM4V, I have a big bar of it sitting and waiting for my next round of steel testing. The heat-treat curves and overall makeup make it look like it will be a nice 'upgrade' to A2 (provided the toughness is as advertised) with more corrosion resistance, better finishing, and capable of even higher hardnesses... I think that would make a seriously excellent kitchen knife (as I know A2 would as well).

 

[aarongough]

So just as a follow up:

I've been using this knife a bunch since I finished it and I will admit it's growing on me. The shape of the blade (more french style than I'm used to) has had an immediate effect on my cutting technique, and has actually made me quite a lot faster which is nice.

Also I initially thought that the 1/16" thick blade would be too thin, but it seems fine in use!

I'm still not a huge fan of the handle, but next time I'm sure I could do better!

Thanks to Don Nguyen for feedback on the blade profile, and to everyone for reading the thread and providing help/feedback!

 

[Omega Leather Works]

I have long wondered why the disdain for CA. I don't use it in my glue ups simply because of the flak, however, I have never had a failure in any case where I have used it. I guess I'll also look forward to the long term test results. I feel like the only way to discredit it's use is to detect failure after a period of time, but however long that may be I don't know. I guess it brings to mind the fiber spacer argument. I've had great success with it (pre-soaked in CA mind you), but folks started to see issues with it from makers that had used it many years ago.

Aaron, do you have any ideas on accelerated wear testing for this? Water sounds smart, what about some rapid heating and cooling cycles? I'm no engineer so I don't know the validity in terms of how quickly found data translates to the actual long term. Maybe there's a chemist roaming the boards? In any case, I look forward to your discoveries.

Anthony

 

[james terrio]

Aaron, as a friend and colleague I feel compelled to warn you... making kitchen blades is remarkably addictive. I've made all sorts of knives and I don't think there's any other style that has so much challenge in it when it comes to design and performance. It's a subtle science... but truly really fascinating and fun

After speaking with several clients and spending many hours discussing this topic with the guy who wrote the last few editions of "Joy of Cooking" (Ethan Becker, sorry for the name-drop ) ... one thing I can say about the edge profile is this: straighter is better, and a lower tip is better. There's a dang good reason santuko's are so popular... they're very easy to use. It doesn't take much curve to get a good "rocking" cut on the board, and the point doesn't do a whole lot of good if you have to raise the knife way up to use it.

Also, the handle should mostly be "not in the way". Less is more. Almost every "proper" chef knife technique involves a pinch grip.

I've only ground a few kitchen blades out of AEB-L... my experience so far is that it's best to take 'em right down to finished dimension before HT. .005" at the edge or less. I've had zero problems with warpage. HOWEVER, bear in mind that I have Peters HT my blades... I have no idea if that would work in your shop with plate-quenching etc.

Simpler steels like O1, 1095, etc are MUCH more likely to warp badly when ground that thin before HT, in my experience. I've come to accept that as not worth fighting, and in future I will just grind 'em after HT.

As for hardness... I continue to experiment with that. My current batch of AEB-L was tempered back to 60Rc, and I'm pretty happy with that. One of these days I'll have some run at 62Rc and see how that goes. My current thinking is this... anything less than 60Rc with full cryo simply isn't making the most of that steel... might as well use AUS-8 or 440A at that point.

 

[Don Nguyen]

Aaron, as a friend and colleague I feel compelled to warn you... making kitchen blades is remarkably addictive.

I think it's already too late for Aaron

 

[Willie71]

James makes great points. When I started with chef's knives, I thought "how hard can it be?" Well..... There is a lot to learn. I am doing blades nearly flat now for most users. As James said, you don't need a lot of belly. Edge geometry is very critical, and this is where my current learning is focused. At first, thin is the focus, then appleseed, offset, microbevel etc all start coming into play. In terms of hardness, I was using Rc60-62 a year ago, and now am Rc62-64. I can feel a definite difference in wear resistance when sharpening. I strongly suggest octagonal Wa handles for most users now. A lot prefer the esthetics of the western handle, but in use, the Wa wins hands down. 3/4" at the blade end in height, and 1" at the heel less than 1/2" wide at the blade end, and under 3/4" at the heel adjusted until it feels neutral is working for me right now.

This isn't a pure Wa handle, but I convinced this customer to try it, and his next knives have all been Wa handles, including an order for 6 steak knives, and a parer.

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