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JohnCenter

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Posts posted by JohnCenter

  1. 8 hours ago, Brian Dougherty said:

    Most people use a belt grinder for the final grind, hence the dime thickness rule of thumb.

    Even a cheap 1x30 would be better than trying to hand sand from 0.040" to a sharpenable edge.  For smaller knives like that it would get you by.

    So what is the rule of thumb for people hand grinding?

     

    when I asked a while back about files vs cheap grinders:

    I was told not to waste my money and time and learn to accept abrasives. I've no problem with hand tools, except now they simply don't work and I have metal to remove. I feel misled. And confused...?!

  2. I've definitly learned that lesson! Wow. 

    But I'm also so very confused.... I always read: grind only to 'dime thickness' to avoid warping and cracking when quenching. But dime thickness is about 0.040"  which is way to thick for me to finish once hardened.

    So what should I actually be doing? Grinding to 0.015-0.020" before heat treat? Or is that too thin?

     

  3. What a nightmare!

    Finally recived my first batch of knives back from the heat-treater. Being my first batch, I experimented a bit. Also, it goes without saying, my consistency is not that great yet.

    Of the four knives I sent, all are 3.50" blades 1/8" thick and 1" wide:

    2 are Scandi grinds with one having an edge thickness of 0.010"- 0.15" the other, at 0.020-0.25". I'm pretty happy at how consistent the edge turned out ( as in not too wavy.).

    2 are sabre grinds going back 0.75" of the blade. One of the edge's measures between 0.020" to 0.30" thick. The tip and near plunge being thicker and the middle and belly being thinner. Not too bad...

    The last is a nightmare at a thickness of 0.040" almost the whole edge. A nightmare because trying to thin out that edge with sandpaper is going to cost me my shoulder and wrist cartilage... Seriosuly. No exaggeration.

    So if the key is to get this bevel's edge  down to at least 0.020" (or even 0.015" as advised above) before putting on the primary bevel with my Lansky kit... how do I do it?

    I've been going at it with 100 grit sandpaper and making very little progress considering the effort and time I've put in.

     

     

     

     

  4. Thank you for the post Steven. I don't have a grinder (maybe I should stop saying, 'grinding'!) I am using only files, but I definitely gleaned some good information from your post. I basically have been doing what you said. Filing a wide angle to my center lines, then pushing the shoulder back to get the angle I want (for scandi) or the depth (for sabre). It has been going well and quite accurate. I have not yet had to 'chase' shoulders from side to side. 

    Brian, forgive me your leaving out such important information! Of course the type of knife I am making would dictate the thickness... This knife is a 4" long Bushcraft type knife. 1/8" thick. 1" wide. So, would your advice still be to have it filed down to 0.015" before putting on the secondary bevel/sharpening?

  5. Re-reading everything, and with respect to the posts above, is their an actual thickness I should have the primary bevel at before grinding the secondary on it? I referenced 'dime thickness' before, but in reflection I'd rather have a number. 0.030"? 0.025"?

    When I measure a dime, it comes out at 0.044". A bit thick I think.

  6. I want to try and make a puukko using O1 and a stick tang design similar to the Polar's and Laurie's that are sold by Brisa. I have my steel heat treated by  a local professional (digital oven, etc.). As a beginner,  I assume this means the stick tang as well as the blade will be hardened when done (59-60 Rc.). I don't know a lot about this kind of thing, but  I remember reading that most puukkos are hand made so the tang is often left softer than the actual blade.

    If that is the case, will I be able to peen the hardened O1? Or do I have to request the heat-treater do something specific?

  7. Experimented the other night. I used a piece of annealed and a piece of tempered carbon steel. Used nail polish as a resist and just quickly scratched some letters with a safety pin. Cut the end of a laptop power supply cord and hooked up the wires with alligator clips. Worked quite well. Definitely going to refine the setup and buy some stickers. One note worth sharing is make sure you have your positive and negative correct. Only works one way!

  8. When working with canvas, linen. or paper micarta scales, what are the basic precautions I need to take? I am having difficulty figuring out a basic standard on the internet.

    Currently I use a 3m half mask with a P100 2091 filter. I also wear wrap around safety goggles, but they are not sealed.

  9. I was also under the impression BLO needed more than a 'soak' to work, but at this stage in the knife-making game I'm willing to be open minded. I did not know it was not water proof.

    So far I've have kept things really simple. I've just been wiping thin layers of Tung Oil onto my wood handles. I've been happy with the results. It dries hard and clear and I haven't had any moisture issues yet.

    I originally went with Tung Oil because I found it locally in a pure form. This made it a generally safer oil to use than BLO, which is filled with chemicals.

  10. I am curious to try this, but have no electrical experience or understanding! Can someone please explain what the the dangers of electrical shock are. Also, what to do or not to do to avoid being shocked?

    @Jason McEntee- Your mark came out really well! Two questions:
    - Was that with the salt water mixture as the tutorial described? Or did you use another solution?
    - You wrote, "I found that a simple 12 volt / 2 amp power supply was more than adequate." Could you post a  link to the product so I can have a better idea of what I need to buy or lend? I'm not sure what that box with the red and black wires coming out of it is.

  11. I've been meaning to ask about a  post I ran across (lost now. I think it was Instagram...) where a knifemaker mentioned he left his wood handled knives soaking for a week in a mason jar filled with a mix of Boiled Linseed Oil and Turpentine. Removed it, let it dry, and sanded smooth.

    Anyone have any thoughts on this process?

     

  12. Right, but I would imagine any discrepancies (within reason) on the dime edge for a scandi can be ground out as you work the bevels down.  With the saber, if the dime thick secondary bevel is being used 'as is' for the primary, then anything other than a consistent thickness down the edge will lead to an equally inconsistent primary bevel.

    I am just guessing as I've yet to reach and experience this stage in my journey.

  13. This is something my search skills have not been able to find a clear 'A-B-C' answer too.  I have some blanks going out for heat treat (stock removal, O1). I am not clear on the steps to get a sharp edge for a scandi or a sabre grind after I get the knives back.

    I only have hand tools. I left the edge approximately the thickness of a dime as per the recommendation of the heat treater.

    My understanding so far:

    1) Soak in vinegar for 24 hours to help remove gunk from heat treat.

    2) Finish cleaning with high grit sand paper

    3) For Scandi edges: Wrap sandpaper around a file and go back to my filing jig.

    4) I figure Scandi's are easy- Sand the edge from dime thickness to zero hopefully ending up around 20-24 degrees inclusive. Right?

    But, for a sabre ground, what do I do?
    Follow steps 1 & 2, but leave the 'dime thickness' and grind the secondary bevel (approximately 20-25 degress inclusive angle) directly on to it? Or does the edge still need to be reduced first? How much?

     

  14. I was curious- When building a  simple folder with a wood handle/slabs- when are liners necessary? Always?

    The only folders I can think of that do not have liners are the Opinels. But they do have a metal ring around the pivot area that on some models provides a lock, but otherwise strengthens the key area.

    Can a folder be safely made with only wood? Are there any important design considerations to be made when choosing not to use liners? Pivot pin selections, washers, etc? A metal ring?

  15. I'm not sure what to say. A wealth of information shared and I definitely have a better understanding. Now for practical application!

    I guess you are right Joshua. It isn't really about tang design, but about getting a correct fit regardless of design. An example of looking at something from the wrong angle on my part.

    I'm familiar with the Nordiskaknivar blog. Lately it is permanently open in my browser. It is also the reason for many frustrations. The knives posted are incredibly fine made. More like jewelry than tools!

     

    Aiden, for your reference to wood: Do you go for a perfect fit? Or use some type of filer for gaps? Glue mixed with saw dust? Or you mentioned soft wood? Isn't that visible?

    Do you peen or is it an all glue hold (like Roselli's)?

     

     

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