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Alan Longmire

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Everything posted by Alan Longmire

  1. Alan Longmire

    Saw blade kitchen knives?

    So much for the chapter on Japanese kitchen knives in "Knife" by Tim Hayward...
  2. Alan Longmire

    Saw blade kitchen knives?

    They are chisel ground. Flat or ideally slightly concave on one side with a half-height bevel on the other. Like most Japanese blades there is no secondary bevel.
  3. Alan Longmire

    Saw blade kitchen knives?

    You can definitely HT both 1075 and W2 with a pipe in the forge, they're simple steels. As for bringing out hamon, the usual procedure is to sand up to 2000 grit, then gently etch with ferric chloride or hot lemon juice, then gently polish with powdered abrasives in oil. Simichrome/Flitz and Mother's Mag Polish can also be used to clean up the blade above the hamon, but they can also erase it if you're not careful. There is a ton of info about polishing for hamon on the forum, look around.
  4. Alan Longmire

    Saw blade melt (failure?).

    Is there any writing on the blade? The ones I am used to seeing often have "Uddeholm" stamped or etched in them every few feet, and Uddeholm is the maker of 15n20, so it's a pretty good guess that's what they are. And 15n20 is slow to rust.
  5. Alan Longmire

    Saw blade kitchen knives?

    If you go with Aldo, his 1075 and W2 are great for hamon. And sometimes the W2 comes thin enough for easy stock removal. Not sure about spine thickness on a nakiri, sorry.
  6. Alan Longmire

    Finish or Not

    Nice pattern, though. You could try the coffee etch and see what happens. 52100, despite the chrome, etches almost as dark as 1095. For more of "pop" nickel is the stuff, thus the 15n20. You could also cold blue it and sand back the high spots with a hard backing on the paper, your etch looks deep enough to make that work well.
  7. Alan Longmire

    Saw blade melt (failure?).

    That's a hearth melt, not a smelt (since you started with steel and not ore), and that kind of bandsaw blade is more likely to be a 4xxx-series band with HSS teeth. If it's monosteel it's often 1095. The ones that they use 15n20 and L6 for are 9 to 12 inches wide with great big nasty lumbermill teeth. All that said, I think I'd give that a miss next time.
  8. Alan Longmire

    304 / 308 Stainless

    It's pretty much impossible. The 300 series is not hardenable. And yes, for the stainless alloys used in knives you will need an oven to get the best results, or any results with some of them.
  9. Alan Longmire

    Seeking advice

    I believe that to be the case.
  10. Alan Longmire

    Saw blade kitchen knives?

    Do you mean the little ones for like a skilsaw, or the big ones from lumber mills? In either case the steel type is an unknown. I know a guy who bought a 36" blade with the carbide tooth inserts thinking it was L6, because that's what all the junkyard steel guys said it was. He had the whole thing laser cut into bowie knife blanks only to find out it wasn't hardenable. Not L6, in other words. Unless you can get an answer from the manufacturer, all you can do is take a chance and figure out the heat treat process for the one you have. That's all trial and error. Unless you have an XRF gun handy that will tell you the composition. The scrapyards have those now and the operators can be bribed with donuts... Oh, and no steel is unsafe for kitchen use.
  11. Alan Longmire

    Seeking advice

    The methyl acetate is a plastic, which explains a lot. Like why Tru-oil is waterproof...
  12. Alan Longmire

    linseed oil

    I agree with Gerald, except I do use boiled linseed oil without thinning. Personal preference only, it makes no difference in the end. So what is "boiled" linseed oil? Originally it was literally boiled with a little lead carbonate, which is what allows it to dry. Now it has been heated enough to polymerize, and the lead has been replaced with petroleum solvents and cobalt carbonate, AKA Japan dryer. Still poisonous, but not as insidious as lead. If you want to make your own, get a jug of flaxseed oil (guess what: it's raw linseed oil. Linseed = linen seed, linen comes from the flax plant, marketers realized nobody wanted to be drinking what sounded like a wood finish) and some lead. Melt the lead in a reducing atmosphere and hold until it's a reddish powder. You need about a tablespoon for every gallon of oil. Heat the oil until it looks shimmery, add the lead carbonate and stir. Keep it simmering for an hour or so, then pour into an airtight container and let cool. Or just go buy some.
  13. Alan Longmire

    Wrought san mai

    I wouldn't go that far. In fact I would take it to almost sharp to make sure the core steel hardens properly.
  14. Alan Longmire

    Hardening a throwing knife

    I suspect they insisted on hardening on FiF to see if people knew enough to temper way back. The guys who didn't break did just that.
  15. Alan Longmire

    Hardening a throwing knife

    Then you'd just get the edge to crack. You really do not want throwing knives to be hard. They break. Springy ones can also throw themselves back at you on a bad throw. I know, people do it all the time. In my opinion it's just not a great idea.
  16. Alan Longmire

    SanMai Bowie Blackwood

    It can. That long clip and the san mai pattern are too cool!
  17. Alan Longmire

    Wrought san mai

    Not to hijack, but that is one nice-looking dagger, Josh! Can't wait to see it finish with the hamon polished out. Yous too, Jeremy. The wrought san mai ought to look spiffy. Just watch for warping and oil quench only. I've had wrought/1095 san mai split up the middle of the 1095 in a water quench.
  18. Alan Longmire

    Hardening a throwing knife

    In that case, just normalize (heat to medium red and let cool) and use it safely! If you feel you have to harden and temper it, which I do not recommend, follow Zeb's advise, quenching in oil (old deep-fry oil is great!) and temper for two one-hour cycles at 450-500 degrees F (232 - 260 degrees C). If you have the means to take it to 750 F (400 C) that would be even better. You want a full spring temper, not hard at all. 1095 tends to be very brittle at best, but if you go for the higher temperature be sure you get there. There is a zone between 275 and 350 C called the "blue brittle" zone when tempering. You really don't want it there. If you are looking for temper colors, the lower end is a light blue and the upper end is gray.
  19. Alan Longmire

    Seeking advice

    I was gonna let them figure that out for themselves. Alex's method works extremely well with Tru-oil on walnut. Tru-oil dries a bit thicker and more plasticky than most, and really fills the pores well. And finally, thinning drying oils like those mentioned above to increase penetration doesn't really work unless you're using vacuum and pressure cycles. Thinning it just makes your life harder because you have to put on more coats, plus you get to pay more for the privilege of letting solvents evaporate from the surface. This doesn't necessarily hold true with end grain wood, which does soak up thinner oils to an extent. But not nearly as far as you might think. The old standard 50/50 mix of boiled linseed oil and turpentine only penetrates maple about 0.020" at a maximum. A bit deeper on walnut due to the pores. If pressurized you can get full penetration, which is how they did military rifle stocks back in the day. Although based on the funky smell of some of the Enfield wood I've cut over the years I suspect the Brits were adding creosote or something vile and petroleum-based to the blend. Don't believe me? Finish a few slabs of wood with various degrees of thinned linseed or tung oil, allow to cure fully, say three weeks, then cut them in half. Get your microscope ready to look for the depth of penetration. Very thin non-drying petroleum oils like sewing machine oil will penetrate all the way through, and will prevent rot and shrinkage, which is why I use it on my hammer handles.
  20. Alan Longmire

    Canister alternative or hacks?

    Don't ever worry about calling BS on me! I was specifically talking about canister welding using powdered steels, and while yeah, you can do it by hand, it is not cost-effective and has a high risk of failure. The powder guys try for a 50% reduction on the first heat, which is pretty tough to do by hand. Now, the kind of canned mosaics that Gary Mulkey is producing lately are easier to weld up by hand than powder steel by a long shot. Still not what I would call easy. When you get down to it, I guess I should have said "you will really put more effort and risk into it than it's worth without a press if you're using powdered steels" than the way I phrased it. Almost everything we do can be done by hand, but there is a point of diminishing returns with several of the processes. I also have a different perspective on what's best than I did when I started out, because I (a.) have a power hammer and (b.) friends with presses nearby. I also have some arthritis issues that limit my hammering time compared to when I was younger, so I tend to try for the most efficiency per swing rather than trying to brute-force my way through. But again, feel free to question me on anything! I am no expert on any of this stuff, I've just been doing it for 21 years so I know what works best for me.
  21. Alan Longmire

    Hardening a throwing knife

    On a throwing knife, especially a mystery steel one, do not attempt to harden and temper it. Just heat it up to watch for that shadow Zeb mentioned and let it cool in still air. If you saw the season premiere of Forged in Fire, you would see five out of seven hardened and tempered 1095 throwing knives break. In my opinion, your best choice for a thrower is 5160 (most automotive leaf spring) left as-forged and normalized (the shadows/cool in still air thing). That will give you extreme toughness with little to no risk of breakage. You can even use plain old mild steel, and when it bends just bend it back straight. Hardening a throwing knife just greatly increases the chance of breakage and possible injury to you or a bystander.
  22. Alan Longmire

    Seeking advice

    Boiled linseed is great, it just takes more time and labor than the other oils. Properly done it looks great. And Joel, yes. If you hadn't already oiled it I'd say to wet sand with water, then raise the grain and sand again. Since it's oiled, oil it is from the start.
  23. Alan Longmire

    Making a dogs head hammer.

    To make the slanted eye you use the same punch, but you taper the body of the hammer itself so that when it's flat on the anvil the punch automatically makes a slanted eye. My 3.5 lb. saw-doctor's hammer is about 2" at the face and tapers to about an inch at the eye, 6 inches away. On the one Owen Bush made for me the slant is not as pronounced, but the handle is twice as long. It's about 2 inches at the face and 1.75 inches at the eye, about five inches back.
  24. Alan Longmire

    Forging in the wind

    If you have a hood and chimney, not so much. If you're using propane and you don't have a powered exhaust fan it can get pretty hot up there. Larry Harley had a chimney, but also low ceilings. He could tell it was time to open the door in winter when the fluorescent lights started going out. I only saw this happen when we were making crucible steel, running the big gas forge for three to four hours at full blast welding heat. Old-style magnetic ballasts start acting up when they hit 120 degrees F or so. Here in the southern US, shops in the days of charcoal-only forging didn't usually have chimneys, but rather a cupola at the roof peak that could be opened and closed. With coal a chimney is a must to get that nasty smoke out of the shop. In the winter when the shop is closed up tight I will sometimes crack a window to let in a little extra air, and I also have an old ceiling fan I run in reverse to keep things circulating. In the summer I have a gable vent fan running as well.
  25. Alan Longmire

    seeking advice on my burner

    I just realized I got the price wrong on the Black Beauty burners. They're $50, not $75. Even better!