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Thread: Road to knife making - The unfolding story of Merwe Knives

  1. #31
    Sharp Shooter
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    The update on the knife making effort:
    I've by now made lots and lots of handle material while I waited for the grinder.

    So Thursday afternoon we went to collect the grinder and got to meet both Tinus and Gawie Herbst, friendly helpful people with a workshop to drool over.
    Tinus told me on the phone the grinder is bigger than it looks in the photos but I was sure it would fit in the Pajero so I left the Venter trailer at home...

    After a lot of manouvering it started to look like I would have to leave Linda or the grinder in Pretoria, front seats moved forward under the dash but eventually we managed to fit me, Linda and the grinder into the car and Tinus was sure I would have to sell the car and grinder as a package cos it won't come out the car again
    The grinder stand legs are not detachable so the footprint is akward and large, glad I do not ever have to package those for export...

    Back home after some scheming and coffee me and Linda had the grinder out the car and plugged in to start up. A sturdy piece of machinery, solid and precise so no belt drifting or wandering once tracking is set. The motor is powerful and does not labor no matter how hard you lean into the grinding.

    The variable speed is a must like Rodders said, this I realised even before I started grinding blades. I spent Thursday evening doing a lot of grinding chores to get used to the machine. I sharpened my axes, de-burred the mushroomed heads of my cold chisels and sharpened everything in the workshop to break in the complimentary 60grit belt I got from Herbst. I finally profiled the "Alpha Bowie", that machine eats steel like a hot knife goes through butter:

    I started with the supawood profiles to figure how I'm going to grind the blades and realised the Herbst grinding support is too big for what I have in mind so I built a prototype support with a small flat support on one side and a pin support on the other:

    The machine is like a meccano set, lots of options and many combinations of doing things.
    The pin idea does not work for me:

    I took Smokepole's advice and started with mild steel blades to test the different techniques and after my second try on the small flat support using a push-stick I managed a neat hollow grind on the mild steel:

    Some early observations:
    Get a leather welder's apron for grinding.
    Mount one or two desk lamps right at the grinding wheel.
    Water bucket under the wheel to catch metal dust and sparks.
    Use welding magnets (I used them for meteorite hunting) to hold blade for flat/tang grinding to save your fingers from getting consumed by 60grit sandpaper. (Vrystaat take note )
    Boilermaker's blue marking spray that's been sitting on my shelf for years comes in handy now for marking grind lines.
    A push-stick is handy, the steel gets HOT unless you don't mind your fingers resembling some amphibian skin after a few knives.

    On the topic of manicure; I lightly smear my hands with Sunlight liquid before servicing motorbikes or doing a grimey job, it prevents the grime from getting into skin pores so a light scrub with nailbrush have your hands look like a surgeon's hands again.

    So tomorrow I'll build my final version of the small flat grinding support then do two more useless but cheap mild steel blades before tackling the first real knife blade
    Last edited by DvdM; 07-04-12 at 01:55.
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  2. #32
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    Very nice, remember not to overheat any part of the blade at any one stage (especially when grinding steel that is to be hardened) or the sharp / cutting edge too thin, as this can cause deformation later on with the tempering stage! One tend to overlook the temp when using a push-stick.
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  3. #33
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    Derek ek lees hierdie met aandag.
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  4. #34
    Sharp Shooter
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    Long weekend has come and gone. I have a total of 5 blades ready for heat treating.
    I'm minus some skin on two knuckles, saw enough metal dust in the bottom of the bath every night to convince me to start wearing my dust mask and to consider building a stainless recovery from bathwater plant

    Let me share this with those taking the first steps:
    My mild steel test runs went very smooth and had me all excited because: The spines of my experimental blades were perfectly straight.

    So I decide to tackle the first stainless blade and in my over confidence decide on this wicked curve-spined blade. Needless to say, the blade ended up in the dustbin, the steel was too thin for the super high grind I had in mind (ended up looking like a Minora blade ) and because I rely on the mini grind table as rest for the spine the curves worked out all wrong.
    I was so heartbroken that I contemplated doing the tanto blade thing, (could become the tanto specialist in SA), those blades have an uncomplicated straight grind and straight spine.
    My next try was a paring knife, fairly straight narrow blade and spine. It was a success and I suddenly got the hang of it, brain spoke to left hand as to right hand and everything just fell in place. Then followed a skinner and two hunters and another paring knife. I started on the "Alpha bowie" and got the grind going before packing up for the weekend, that steel bar is 6mm thick so I have some serious grinding ahead but is well on my way.
    Part of the trick I found was to quickly establish a grinding groove for the wheel after doing the 45deg edge thing with a worn belt.

    If you start too slow and too careful the groove is all over the place. Once the groove is deep enough you can actually 'feel' it when bringing the blade to the wheel before applying pressure to actually grind. The moment I lose concentration things go wrong, even just moving the light or shifting my stance before the proper groove is established on both sides of the blade makes me wander all over the blade again before the eye hand co-ordination is re-established. Once the groove is deep enough to "feel" with the wheel it's easy to find again after a break.
    One should ideally start with flat grinds I guess, if the line goes wrong you just 'blend' it, I see a lot of knives made that way, there's no positive distinguishable grind line. Hollow grinding is unforgiving, it's either spot on or a total disaster.

    To aid the sliding action of the spines over my mini table edges I've rounded and polished the edges of the table. I then also slightly de-burr the spine edges of the blades to facilitate easier sliding over the table edges when doing the curves.

    It's a pity the grinder's height from floor is not adjustable, I'm not a Yeti and feel I might have worked easier looking right down at the wheel, will still try standing on something.

    Well, that's it so far, need to spend some time inside the house now
    Last edited by DvdM; 09-04-12 at 21:52.
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  5. #35
    Sharp Shooter
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    I have eventually completed my first 3 knives with one to go of the first batch. Long story short about jigs and rest plates, there's one practical way to do it and that is freehand. Slow at first until you get the hang.

    Problem with jigs and rests are that every knife's profile is different and unless you stick to making tanto style blades you'll have to adapt your jig for every knife.
    After I got the four blades back from heat treatment I decided to go freehand in finishing them. Since the blades were now so hard I could really take it slow, running the Herbst motor at 500rpm from 3000rpm max. So I stood there, about 4 hours on every blade but I managed to get it right freehand. I could actually correct some of the slip ups I made before heat treatment.

    Also, over heating the blade due to agressive grinding after heat treatment would be detrimental to the blade quality so I took my time.

    The first 3, hunter, de-boning knife and skinner. The de-boning knife is for Linda to test drive in the kitchen and sports my self made cotton micarta:



    The hunter, I'm satisfied with symmetry and grind lines except I'll do a bigger curve at the plunge-cut at the ricasso next time. It will be easier to accomplish freehand.



    So I reconed I'd use the Lansky sharpener to put the 15deg cutting edge on the blade chop chop. Surprise when I realised how tough the 12C27 Sandvik steel is compared to the commercial blades I used to work on with the Lansky so I ended up going back to the grinder with ceramic belt to do the cutting edge.

    I had it shaving sharp in no time:



    The last de-boner with only handle to finish. A long wait since I am using ABE Epidermix epoxy with a 24 hour curing time for handle work. This epoxy proved itself to me when I built laminated bows:



    I won't make knives in batches again, I got a heat treating kiln so don't have to do things in batches. I lose focus on the smaller detail of every knife when working in batches.

    I'm almost there, there's no turning back now, spent too much time and money on the hobby

    These knives were all hollow ground, next up will be my "Alpha Bowie" which must be a flat grind due to the blade width. I got the flat grind attachment for the grinder and cannot wait to try the first flat grind.
    Last edited by DvdM; 18-04-12 at 20:52.
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  6. #36
    Rest In Peace Willie 10/05/2012

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    Default Derek

    Wow!

    Those knives looks stunning. If you start like that, I would like to see where you are in a year or two.
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  7. #37
    Sharp Shooter

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    That is some really beautiful work.

    So when will we be seeing some of these works of art up for sale?
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  8. #38
    Sharp Shooter
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    Thanks for the compliment Willie! Like I said; there's no turning back, there's a MPR, HW77Stutzen and a lot of other very nice toys I sacrificed for this hobby so I must get it right

    Ebe, must first test the steel and get the skills and finishing up to scratch before I can sell

    When I do there must be no come-backs!
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  9. #39
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    Default Hunter

    The hunter,WOW.All of them, wow.
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  10. #40
    Rest In Peace Willie 10/05/2012

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    Quote Originally Posted by DvdM View Post
    Thanks for the compliment Willie! Like I said; there's no turning back, there's a MPR, HW77Stutzen and a lot of other very nice toys I sacrificed for this hobby so I must get it right
    Derek - received stock & stripper today from Paul. Need mounts, hopefully getting tomorrow.

    Then it is me and the MPR getting to know each other - will keep you posted.
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  11. #41
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    The 3 knifes looks great well done to you. keep it up............................
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  12. #42
    Sharp Shooter

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    Great work Derek. I really like the hunter.
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  13. #43
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    Gee, they all look fantastic! Well done.

    Most other first knives would run for cover when they saw yours coming!

    How did you finish the handle on the Hunter?

    Did you use fibreglass resin for the micarta and does it still smell? (I'm looking for a non-smelly epoxy for making micarta)
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  14. #44
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    Beautiful. Well done!
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  15. #45
    Sharp Shooter
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    Thanks for the encouragement guys!
    Rodders, I used normal fiberglass resin. Trick is to get the hardener/resin ratio perfectly right then it sets properly and does not smell after setting. I figured how to use one of my electronic scales to do the hardener/resin ratio.

    The hunter handle is treated oak, I soaked it for a week in thinned down varnish and let it dry for another 2 weeks. The finish is a rough 60grit on a 25mm wheel and then steel wool and buffing afterwards.
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