My 1st knife.. a Sujihiki.

Discussion in 'Handiwork Display' started by Beanwagon, Feb 21, 2019.

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  1. Feb 21, 2019 #1

    Beanwagon

    Beanwagon

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    I started making my 1st knife. I have an extremely basic setup. I have only used and angle grinder and filing jig.

    I still need to send this off to get heat treated.

    I am deciding if i am going to attempt to sharpen this myself or send it away to get professionally sharpened.

    I have never sharpened a knife before and was considering getting the shapton glass stone set 1k, 3k, 8k and a lower grit stone to get the edge going. I would practice on cheap blunt kitchen knives 1st ifni were to do this







    The handle pictured in the second video is just a practice handle i have been working on(also my 1st).

    I plan to make a octagonal wa handle with this dyed maple burl, buffalo ferrule and brass or copper spaces.

    I also plan to etch some add some soet of patten. Just not sure yet. Possibly a fake hamon. Any advice or criticisms are more than welcome.

    20190221_223850.jpg
     
    Last edited: Feb 21, 2019
  2. Feb 21, 2019 #2

    Michi

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    No advice from me, but that maple burl looks gorgeous!
     
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  3. Feb 21, 2019 #3
    That looks pretty impressive for a first knife. I would make it a bit thinner in general (looking at the spine thickness) - say about 2 - 2.5 mm on the spine half way between the heel and the tip and about 1 mm on the spine 1 cm from the tip (give or take, suji does not really need a crazy thin tip).

    You mentioned that it is O1 steel in a different thread - I would leave some 0.4 on the edge before HT to minimize the risk of warping or cracking. You will need to finish the grind after HT - that will not be possible with a file and not easy with an angle grinder (risk of overheating) and would take forever on a stone or diamond plate. You may consider getting a small 1x30" with some 60 and 120 grit ceramic belts for that. Those little machines are more capable than one may think.
     
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  4. Feb 21, 2019 #4

    Beanwagon

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    Thank you!

    I like the knife being thick in terms of aesthetics. But i understand this could affect its cutting ability? Is this correct. If so how?
     
    Last edited: Feb 22, 2019
  5. Feb 21, 2019 #5
    Well, the thicker tbe knife the less easily it tends to move through food (that is a bit too general statement). Plus of course the weight changes the way the knife feels in hand and how it will be used.
     
  6. Feb 21, 2019 #6

    Beanwagon

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    Ok thank you. I am a complete novice to knives and knife making.
     
    Last edited: Feb 22, 2019
  7. Feb 21, 2019 #7

    milkbaby

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    Nice work so far! I agree with Matus that the spine looks a little thick though.

    Looking forward to more pictures, very nice first knife so far!
     
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  8. Feb 22, 2019 #8

    merlijny2k

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    +1 to the above. For a sturdy survival knife you can consider doing an almost zero grind before HT and have a reasonable chance of success but for a knife as long and thin as yours I don't see how that will turn out successfully without finishing the grind on a beltgrinder. Nice job so far in any case. Looking forward to the result!
     
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  9. Feb 22, 2019 #9

    Beanwagon

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    I do not own a belt grinder . I definitely would like to own one. i could file it on my jig post heat treat instead but i would assume this would take a lot of effort?

    Every thing i do at this stage is trial and error and crucial for my learning so i am happy to experiment even if that means take the long road.
     
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  10. Feb 22, 2019 #10

    Beanwagon

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    After reading your post i grabbed my knife to inspect the edge... maybe i inspected a little too well. I suppose thats a good thing stat it hasnt been sharpened yet but can still cut. Probably not pre heat treat though

    20190222_212150.jpg
     
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  11. Feb 24, 2019 #11

    merlijny2k

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    Problem with filing post HT is the knife will be about as hard as the file : the hardness of hardened steel. There is a range in the hardness of hardened steel and theoretically you can get a file at the far upper end and it might work if your knife is well tempered. No experience with that route here and I don't know of anyone who does it. Extremely hard files are very expensive. 100-150 ish.

    If you don't mind the time you can start on a course stone (can be had for 5. That's how I started) or a diamond plate (100-ish). Some of us started that way. Typically thinning project knives rather than building a full size built from scratch suji.

    Thing is a simple belt grinder can be had for 150-225. So it is kind of in the same pricerange as a good diamond plate. Of course for the grinder you need more space, safety gear (goggles, mask with HEPA filters! Especially when doing wood sanding but I always wear it now, leather gloves are optional).

    So:
    Cheap soft course stone: completely useless you grind through it in the first two hours.
    Cheap hard course stone: cheapest option. Takes lot of time. Don't buy an expensive course stone for this. The improved quality with buying an expensive stone is in a more even grain. Very nice for sharpening or finishing a thinning job (no deep rogue scratches) but a waste for thinning a bulk of metal off.

    Diamond plate: bit faster and bit more expensive. Don't have one so can't tell how much faster. Matus did some impressive work on one.

    Cheap grinder: much faster, risk of overheat. Takes more space.

    To give an indication of speeds:
    Course stone takes just under an hour to remove 0.1mm of steel on one bladeface. 10h and up thinning jobs are no exception. 2 hours wears you out because of concentration levels required so space over multiple days.

    Grinder is about 1mm per hour depending on HP and how often you switch belts. Cheap belts wear faster amd expensive lasts longer. Production per dollar tends to end up the same-ish. So don't worry too much about selecting a belt if you decide to get a grinder.

    Hope this helps with the planning.
     
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  12. Feb 24, 2019 #12

    Beanwagon

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    Thanks for all the info! I definitely have to weigh up my options. Although not preferable i definitely do not mind spending time to do it the long way. I could always thin the spine out with an angle grinder/file jig pre heat treat. I feel like i wont have to remove too much post heat treat? Snapchat-1483343487.jpg
     
  13. Feb 26, 2019 #13

    merlijny2k

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    Your knife at present is quite a lot thinner than advised for going into HT.

    So were mine. They both came back bent. I succeeded in straightening both using the chisel hammer method. (Already an extensive thread about that topic). If the edge bacons the knife can be considered lost. Fortunately that didn't happen.

    I think the advised edge thickness for HT is about 1mm. Even though I succeeded finishing the knives next time i'm going to stick to the guidelines myself. You learn a lot straightening a blade though and it is surprisingly fun.


    In traditional Japanese knifemaking from before the beltgrinder era san mai (hard core soft cladding) is used. That way you can thin to the core with a file.

    I don't know how western knifemaking was done pre-powergrinder. Would like to though :)
     
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  14. Feb 26, 2019 #14

    JustinP

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    You're definitely a better knife maker than knife inspector :D
     
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  15. Mar 4, 2019 #15

    Beanwagon

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    I have had people in other places tell me that because the spine is so thick 5mm+ it shouldnt be an issue?

    As you mentioned you learn a lot from mistakes/ fixing issues. I just ordered a heap of 15N20 so plenty more material to play around with.
     
    Last edited: Mar 4, 2019
  16. Mar 7, 2019 #16

    merlijny2k

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    Not so sure about the thick spine helping much. I had a 4mm spine and still came back bent. I had a very assymetrical grind while yours isnt't. Don't see how a thick spine would protect against a baconed edge though. Rather the opposite. The martensite transformation causes expansion. If the transformation is complete at the edge and partial at the spine you could see why a bacon edge occurs.

    I have seen experienced smiths overheat the steel a little bit, then aircool to desire temp and then quench. The short aircool causes the thick spine to be hotter than the edge at quench. This shoul
     
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  17. Mar 7, 2019 #17

    Beanwagon

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    Interesting. Well fingers crossed. I will have to ask the company who will do the HT if they are able to straighten if thats the case. Worst case i learn a valuable lesson.
     

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