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Connor Lyons

First Kitchen Knife - Chai Dao WIP

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Just finished the bevels on my first attempt at a kitchen knife. It is definitely my most ambitious knife, but so far I am pretty pumped about how it's coming along. I drew up the design for it with the idea that I wanted a sort of cleaver/chef's knife crossover, and upon doing some research (after I had profiled and ground the bevels) I've  discovered that it pretty closely resembles a Chai Dao. It is made from .110" 80crv2. I plan on giving it to my cousin who is a professional chef. My cousin being a true cutlery enthusiast, i hope to get some real feedback on how it performs and how I can improve it. I myself am a lousy cook and have nothing to compare it to seeing as I have never used a carbon steel knife in the kitchen.

 

My main goals with this knife are to get a feel for how to grind a slightly convex grind across a really wide blade, and achieve a slight distal taper in the process. This is also the first knife that I have used my new and improved filing jig to file the bevels. And I must say I'm effin stoked with how it worked. Anyway, on to the pictures.

 

I'll start by highlighting my jig setup:20171104_024353.jpgBasically a much more rigid version of my old wooden jig. Its made out of 1/8th" thick 1X2 box steel. I've draw filed the surface where the blade is clamped to try and get the flattest and most consistent surface possible. I did my best to keep everything as flat and symetrical as i possibly could. And I sure got some practice drilling and tapping holes. I discovered I could easily mount my file cleaner to the other side of the jig, which proved to be super useful. Much faster than having to stop and pick it up.

 

20171104_012618.jpgHere you can see the plunge line stop pin with a steel sleeve around it to act as a bearing for my file to roll against. This keeps the file from grinding into the stop pin and pushing the plunge line farther towards the ricasso. The little brass piece is just a spacer to keep the sleeve from sliding up too far and allowing the file to slip underneath it.

 

20171104_051949.jpgMy plan was to grind to my edge centerline and then bring the grind angle down gradually. As the bevel pushed it's way up towards the spine I lowered my angle more and more to create a sort of faceted effect to achieve a slightly convex grind.

 

20171106_052329.jpg20171106_055616.jpgHere you can make out the progression of the different facets going all the way up to the spine. Once I got about halfway to the spine my file started pinning a whole helluva lot, and having the file cleaner mounted on the jig proved invaluable as I was having to clean my file at least every 3 or 4 strokes. It also became really hard to keep the different facets running evenly down the length of the blade, you can see how they dont perfectly follow the profile of the edge. But I hoped this would all be buffed out in sanding. You can also see that my front stop pin is brass so my file could easily peel off the top of it when the angle got really low.

 

20171106_063649.jpg20171106_063727.jpgAfter filing the first side I decided to go ahead and sand it with 220 grit while it was still in the jig. I simply wrapped my file with sandpaper and reversed the direction I worked the bevel, going from the spine down to the edge. It was lightning quick! Way faster than hand sanding out of the jig. And to my surprise and pleasure, no signs of pinning across the whole thing! It also smoothed out the whole grind to where the different facets have blended into a smoothly transitioned convex grind.

 

20171110_043518.jpgFor the second side I did everything the same except I used a thin piece of brass to shim the underside of the blade to try and compensate for the slight distal taper forming towards the tip. Without this the tip of the blade would get pushed down by my file and I worried it would affect my grind angle. But even with the shim, the tip was pretty flexy, and I had to use as little downward pressure as possible. No one said filing bevels is quick...

20171113_054140.jpg

This shot is looking down the edge from the heel of the blade. Clamping the knife to the jig on the second side is always a bit challenging because you have to get the plunge lines lined up as best you can. I was really pleased to see that I got them lined up within a few thousandths of an inch, definitely my most symmetrical grind thus far. This is also where having the edges of the file chamfered at a 45 degree angle is important. I took my edge down really thin to around 15 thou, which im hoping will allow for a really sharp final edge, but I'm also really nervous about how that is going to go in heat treat...

20171112_064151.jpgthe only part of the spine that shows signs of a distal taper is up towards the tip, but i think this is mostly because of the shape of the profile. My next kitchen knife (I already have one profiled) will be a more European style chef's knife and the drop point profile shape should hopefully produce a more pronounced distal taper.

 

20171113_054531.jpgAnd there she is thus far! I'm already filled with nervous excitement over this one. My dream is to one day create high quality kitchen cutlery that above all else, performs as well or better than commercially available knives. I feel this knife is a small but important step towards one day getting there. 

 

I'd say I spent at least 10 hours purely filing away on these bevels over the course of 3 or 4 days. And lemme tell ya, it is as brutal as you'd expect. It is quite an arduous task. But a word of advice for those who file bevels, HEADPHONES. This would not be possible without being able to listen to something other than the squealing of my file for hours on end. Personally I really enjoy listening to some podcasts or an audio book as I dig into the seemingly eternal tedium. But every now and then I have to listen to so some good ol' death metal to really get in the spirit of shaving metal.

 

Please feel free to offer any criticisms you might have about what I could have done better up to this point, and or advice for moving forward. Unfortunately it is going to be at least a week or two before I get back to my forge to HT. And I gotta say I'm pretty nervous about it seeing as my edge is so thin, and I have never worked with 80crv2 before. My plan is to normalize a couple times then quench in canola oil, and probably give it rwo or 3 temper cycles at 350 or so. Any reccomendations here would be greatly appreciated.

 

 

 

 

Edited by Connor Lyons

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Very nice Jig and WIP!

You should read the topic 80crv2 in the heat treat per alloy tread. This steel requires soak times to get the most out of it. Grain growth is not a concern since the vanadium keeps it small. 

Edited by Joël Mercier

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22 minutes ago, Joël Mercier said:

Very nice Jig and WIP!

You should read the topic 80crv2 in the heat treat per alloy tread. This steel requires soak times to get the most out of it. Grain growth is not a concern since the vanadium keeps it small. 

Will do. Soaking could be challenging with my forge, but i have an extra piece that I think I'll experiment with first. Thanks!

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I used a baffle pipe to HT mine. I did put a piece of wood in to absorb oxygen. I believe it helped quite a lot with decarb. 

You need a mean to monitor your forge temp if you want to soak. I bought a K type thermocouple and reader for around 45$ on Amazon. I screwed it in my baffle pipe. It worked very well.

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21 minutes ago, Joël Mercier said:

I used a baffle pipe to HT mine. I did put a piece of wood in to absorb oxygen. I believe it helped quite a lot with decarb. 

You need a mean to monitor your forge temp if you want to soak. I bought a K type thermocouple and reader for around 45$ on Amazon. I screwed it in my baffle pipe. It worked very well.

Awesome, I was just wondering about baffle pipes and thermocouples. Definitely going to order a thermocouple and a reader today, but i still don't exactly know what a baffle pipe is? I'll have to use that handy search function...

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Very simple mild steel pipe caped on one end. Your knife is very wide so you will need a large pipe. I put my knife in spine down to have a more even heat on the bevels. It reduces warping odds.

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5 minutes ago, Joël Mercier said:

Very simple mild steel pipe caped on one end. Your knife is very wide so you will need a large pipe. I put my knife in spine down to have a more even heat on the bevels. It reduces warping odds.

Sweet, I've got access to plenty of scrap pieces of steel pipe at work, I'll weld one up tonight!

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@Connor Lyons. Just checking you know about not heating or welding galvanised/zinc coated steel.

Edited by Charles du Preez

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Also, you can squash a 2" pipe into a 1" x 3" oval.  Comes in handy!  Just be sure one end is capped and, as Charles said, it's not galvanized.  I galvanized is all you can get, soak off the zinc in vinegar or muriatic acid.  Note this may take a while on really thick hot-dipped galvanizing.  It's better not to use that at all.

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So far I like this steel. It seems very tough and hard. It's a present for my hunter dad so he will be my field tester 

P_20171113_213010.jpg

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9 hours ago, Joël Mercier said:

So far I like this steel. It seems very tough and hard. It's a present for my hunter dad so he will be my field tester 

P_20171113_213010.jpg

A real beauty you've got there. Looks like we've both got some work to finish up before christmas. 

 

11 hours ago, Alan Longmire said:

Also, you can squash a 2" pipe into a 1" x 3" oval.  Comes in handy!  Just be sure one end is capped and, as Charles said, it's not galvanized.  I galvanized is all you can get, soak off the zinc in vinegar or muriatic acid.  Note this may take a while on really thick hot-dipped galvanizing.  It's better not to use that at all.

Yep I certainly won't be using galvanized. Got some schedule 40 lying around the pumphouse that I'll give a good squashing to before I weld on a cap.

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