Jump to content

Alan Longmire

Super Administrators
  • Posts

  • Joined

  • Last visited

  • Days Won


Everything posted by Alan Longmire

  1. And the hammer-in has been and gone, and I'm exhausted. It was GREAT! Pics to come this afternoon, maybe. I'm still reeling from three days of nonstop activity...
  2. Good morning! We have NC Tool and Mama's got Wood as well! And the first demonstration has begun! Robin Lynch doing introductory smithing.
  3. I does look like a Star. Needs the flywheel/pulley, but the clutch is there. The anvil looks great, and Geoff is right on.
  4. What Jaron said! I think you should allow the winner to choose, but that's just me.
  5. The tent is up, forging station will be front and center now. Unfortunately no bleachers this year, chairs only. But it's still going to be great!
  6. That is indeed beautiful work! And you do have more experience with it than I do. I only know brass wire.
  7. Even soft iron binding wire will work-harden if you twist it up. As I said, I've never done a turk's head in metal, but I do know the wire will get hard to work with if not annealed often. With copper alloy wire (nugold is what I've worked with) I find it needs annealing after every step when making beaded wire or filigree wire.
  8. Those look good! And Joshua, I can see the pics now, thank you. What are you building?
  9. I haven't done it, but I assume you're annealing often during the process?
  10. And they're not showing up... Same stuff as last year, except for the cig paper challenge. I bet somebody will manage it, my knife is on the thick side.
  11. The trick with using the torch is to hold it far away from the steel and use slow sweeping motions to slowly and evenly heat the spring. It should take at least 30 seconds if you're doing it right, and up to a minute is even better. But the heat gun may work fine, too.
  12. Spelter! That's the word I was looking for. Zinc alloy, used for all kinds of stuff ca 1860-ish 1970-ish. It corrodes like that. Not easy to fix. The distilled water soak will stop further corrosion, though.
  13. Put together one of the more difficult cutting competition event props: The Tai Goo cigarette paper slice. Roll a gummed paper around a rod. Slide the tube off rod. Stand tube on end, and cut. Tai liked to do it with no support, but I added a 3/8" long dowel for the tube to sit on so it can be done if there's a slight breeze. The object is to slice the tube cleanly in two horizontally. Success requires a perfect edge. Given that this same edge must also slice and stab a ping pong ball, cut a 1" rope, slice as many plastic water bottles as you can, and probably cleave an aluminum can top to bottom, it's also a test of your heat treatment. I've been tuning the edge of my cutter, but it still has a ways to go. I can get halfway through the paper on a good swing, but that's it. And it's already the sharpest edge I've put on a big knife...
  14. I do clean steel with electrolysis, but pewter is well up the galvanic chart from steel, even stainless. This means the steel will be eaten away in preference to the pewter. In this case, the steel becomes the sacrificial anode to the pewter. You see this archaeologically, especially with bronze-mounted steel blades. The copper alloy will be perfectly preserved and the steel will be hopelessly corroded. Pewter isn't quite as strong as copper alloys in that respect, but it's still the more resistant metal. The only bimetallic combos in which the steel will not be eaten first are steel/magnesium and steel/zinc. That's why you see zinc used to prevent corrosion on steel-hulled ships. The zinc will slowly dissolve, leaving the steel untouched. Doesn't take much, either. A few ounces of zinc will protect a few tons of steel. Which brings up a question: How sure are you that that bolster is pewter, defined as a tin/lead or tin/copper/bismuth alloy? If it's actually pot metal/white metal/Zamak, or another zinc-based alloy, electrolysis will eat the bolster before it touches the blade. That's why the chrome-plated gewgaws on old cars (and the bodies of die cast toy cars!) are always crusty and pitted, they corrode while protecting the steel they're attached to. And that's just via the very weak ionic currents in rainwater and other moisture. I suspect that may be the case here, that it's a pot metal bolster that has corroded in deference to the steel. That white crust could be zinc oxide. Unfortunately, tin oxide is white as well, as is lead acetate... I'm sure there's a simple household chemical test to figure it out, but I don't know what that would be. Citric acid eats zinc fast, but that's kind of destructive if it is a zinc alloy... Weight is another definitive test. If it's a tin-based alloy it'll be noticeable heavy for its size compared to steel, if it's a zinc alloy it'll be light for its size in comparison with steel. How about some conservation techniques: To stop the active corrosion on that bolster, soak it in distilled de-ionized water for a month or so. It won't hurt the steel, but it will remove the corrosive salts in the metal of the bolster. After you do that, gentle abrasive cleaning may shine it up. Or not, depends how deep the pitting goes. That will work no matter what the material is. I don't know how common the de-ionized stuff is in Namibia, here you can find it in the grocery store. Plain distilled work, but it's not as good a stabilizer and will need a longer soak.
  15. Unfortunately that won't be good for the knife itself. If the bolster comes off you can use electrolysis, but if you leave it on the knife the blade will pit and the edge will get eaten. If it were me I'd clean it up with needle files followed by fine (P400 and up) sandpaper or steel wool.
  16. The only person I have fought with regarding methods of heat treating was because he was quite dogmatic about things that were just demonstrably nuts. I suspect your use of the induction forge is very helpful with the AEB-L, too. Heating steel.uniformly from the inside out is fairly magical. One of these days... and yep, those tiny carbides and relatively low carbon are the greatest thing about AEB-L. I figure if they use it almost exclusively in razor blades it has something going on for it.
  17. No secrets here, that's part of the spirit of the forum! I never used to soak O-1 either, and sometimes I still don't if it's the steel I have handy in the right dimension for a quick tool. At the 2015 Ashokan hammer-in, Kevin Cashen did a talk with slides about how he does O-1. Kevin is a great guy, a true steel nerd. He is so into it he set up his own metallography lab. He has two Vickers metallurgical microscopes (one is a parts machine) designed to produce images like those Jerrod has posted. He has the lapping machines to produce the micron polish needed to really see the microstructure. On top of all that, he's the only bladesmith I know who is so into steel that he bought an electron microscope . He got it cheap because it needed some hard-to-find part, but still, he has an electron microscope in his shop. Anyway, in his talk he showed some slides that explain what happens to O-1 with no soak, with short soaks, and with longer soaks up to 30 minutes. The basic takeaway is you can certainly do O-1 by eye and seat-of-pants. Heat to bright cherry red, quench, and it's hard. Thing is, you're not getting the utmost performance possible that way. It's fine for 99% of end users who wouldn't notice much difference, but now that I have seen the evidence of what can be done, I hate to do it quick and sloppy. IIf you treat it just like 1095, it's going to act like 1095, and get the job done. But if you treat it like O-1 and use multiple thermal cycles (normalizations) to get the grain refined (assuming a forged piece, if stock removal from spheroidized that's fine, but not strictly necessary), then soak at 1525 F for up to half an hour, you get the fine carbide distribution combined with fine grain, which equals much increased edge holding and toughness for a given end hardness. He did these tests on round bar, not blade sections, so there is room for tweaking the soak times. The simile he used was "Not taking advantage of the full potential of O-1 is like having a car with dual quad carbs and a supercharger, but blocking off one carb and disconnecting the supercharger. It'll get you from A to B, but not nearly with as much performance as if you used the whole thing." And as long as you control for decarb, you still have that lovely long window to quench in. With 1095 you have less than a second to get from 1425 to below about 900F or it won't harden fully. With 5160 you have something closer to ten seconds to go from 1525F to under 900F. With O-1, you have close to a minute to beat that curve. Total relaxation in the quench, in other words. Just don't try it with water or brine! I only have the oven because I wanted to use stainless steels for my pocketknives, and you can't easily do those long holds at 1925+ degrees in most forges. I have a little two-brick propane forge that, once it's warmed up, can be tuned to hold at 1525F all day long. I use that for my O-1 chisels and pocketknife blades just because the atmosphere is better suited to control decarb and there's no foil to mess with in the quench. That said, I snapped the tips on two of my O-1 die-sinkers chisels I use to do silver inlay into steel on the last hawk head I made. I think I'll use the oven on those to get the highest performance I can out of them after I anneal and regrind them. They're used just like carving gouges, but on mild steel or wrought iron. That's the thing with high-alloy steels and soaks: Carbon moves fast, like 1/16" per minute, at 2000F. Tungsten, chromium, and vanadium do not. They take their sweet time. As long as you know the temperature at which grain growth begins for a given alloy, you can ride that fine line for a long time to ensure you get the maximum distribution of the non-carbon parts of the alloy. Thus for forged O-1, I consider all the time at heat while forging as part of the overall soak time. For pocketknives that are stock removal only on stock that is spheroidized, I try to work in thermal cycles and a decent soak. The stainless I use for pocketknives is AEB-L or 13c26. It's the finest-grained stainless I know of, and takes a finer edge than the supersteels. Doesn't hold it as long, but it's easy to sharpen. Behaves much like 1095 in that regard. But O-1 makes a better blade, performance-wise. It just rusts. O-1 is really good about slow grain growth as well. A friend who was getting into repousse asked if I could make her some matting punches. The time-honored way to make a fine textured matting punch is to use W1 or 1095 rod forged to the desired profile, file or saw a notch all around, and bring that end to a white heat and soak for a few minutes. Let that cool to black, reheat to nonmagnetic, quench and snap at the line, and boom! Perfect matting punch texture on the broken end. Well, I had no 1095 or W1 on hand, but I did have some O-1. Even after ten minutes at yellow-white the grain, while noticeably larger than it should be, was still too fine to be a good matting punch. I ended up going to the old bolt and screw shop to buy some W1.
  18. The 52100 I have is in either ball bearing or annealed round bar form, and after forging either into a blade-shaped object I figure it's had enough thermal cycles to obviate the need for a soak. O-1 is another story, but I have Kevin Cashen's micro shots to blame for that. I do appreciate the value of the snap test. It won't tell you much about carbides, but it does tell you your grain size. The old folks knew if it looked like glass it was excellently heat treated steel, just through centuries of practice.
  19. Metallurgy as we know it didn't really become a thing until the 1850s. "Natural philosophy" was the name in the 1760s when actual science became a thing, and that evolved into chemistry and physics by 1790. Metallurgy was a subset of chemistry at first. They didn't figure out that carbon was what made steel hardenable until around 1770. They had theories about "purifying" iron by forging really hot in a reducing atmosphere after baking it in a sealed container of bone charcoal starting in the medieval period, but didn't figure out why that worked until the late 18th century. Once they figured out how to isolate elements things really took off, especially after the Bessemer process came in around 1856. That said, toolmakers preferred cast steel to Bessemer ( and the later technologies) well into the first part of the 1900s. Because it just worked. They may not have even known about grain, they just knew how to make it work.
  20. A lot of those are going to be cast steel, as in made from crucible steel and forged, not cast into shape. This is going to be most similar to plain old W1 or 1095, but with wildly variable carbon from piece to piece. Individual blades will be uniform, of course. It's just clean straight carbon steel, low manganese, nothing else in there.
  21. I was telling someone the history of the place, and the fact that I do not own it, when I realized I myself joined in September 2003. It's now September 2023. Time flies when you're having fun, I guess... Don Fogg started this place as a page on his personal site in March of 2003 (some digging on the Wayback Machine shows he added a forum in December 2001, but it was on a different set of software I can't get to open now. The current InVision Powerboard format we know and love is what he added in March 2003), and I intended to make this announcement in March. Better late than never!
  • Create New...