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Michael Stuart

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Everything posted by Michael Stuart

  1. thanks for mentioning that Sweany I've still got it, have used it several times out in the yard when I couldn't wait any longer to get the main forge put back together after moving. The threads rusted shut once on the cleanout cap, so I tore it all apart and rebuilt a bit better, I would tape the threads to slow the rust if I could find where I put the teflon tape. Instead I give the cleanout a turn every few weeks to keep it from rusting shut again. The filling is scrap cement board pieces covered with yard clay mixed with ash and gravel. It works for coal as-is, for burning charcoal or wood I put a couple pieces of firewood parallel on each side of the grate to let me have a deeper narrow fire in between.
  2. Don, it seems like I've heard there are labs that for a fee will analyze a piece of scrap steel for the dozen or so (20?) elements of interest to knifemakers. But I don't know who offers such a service, or how much it might cost. Any information you might have about this would be welcome.
  3. sickbugs, limestone CaCO3 + heat makes CaO or lime, you're halfway to making either grits or mortar depending on what you add next. Better living through chemistry!
  4. Yummy, just add some salt and a bay leaf or two and it's giraffe soup time Seriously, I boiled a thanksgiving ham bone for hours but it was still a bit greasy and yellowish; a 20 minute boil with lots of borax in the water cleaned it up the rest of the way, but smelled nasty. Then I looked closely and found out it had been 'spiral sliced' all the way into the bone. The surface was starting to break down a little bit from all the boiling. Could be time for a spiral wire inlay, or then again, a treat for the dogs. Speaking of which, some pet store bones are well bleached but still structurally sound. If anyone can suggest how to saw and drill these bones cleanly, I'd love to hear about it.
  5. Thanks. Wow, where's that last one from? I can figure out part of the process, but anytime you want to make one and show how you did it we'll all be grateful.
  6. "with a blade that is 5-6" wide 12-16" long" jon, I'm guessing these dimensions are not just the blade, but including the 'wings' and socket? Most of the pictures I have seen don't list dimensions on the spear heads (or discuss hafts at all) so I'd love to have you share more of what you know about this. That's a whopper of a spear either way and one day I want to try making one.
  7. Ammonia fumes give some varieties of oak a nice dark finish; IIRC Mission-style furniture used this technique a lot. Lots of folks use a soak in vinegar to remove scale from forged iron, but not as many know that the leftover vinegar-iron sludge also makes an interesting black finish on oak.
  8. Jesse, I've had the same experience with the paint on strapping, that is, it burns off quickly and doesn't seem to cause a problem. I had a chance once to get a whole roll of the blue strapping at near-scrap price but it was gone when I came back with my money. Sigh. Thanks Mike for sharing the info on the composition. I was hoping someone might have tracked that down. And thanks again to Don for providing such a great forum for these discussions. I usually check a piece from each sawblade or strap first by heating and a water quench. Then if it snaps it's potential edge material, and if it bends some or even a lot it's good for the non-edge parts or for fittings. It also gives me some idea of whether I need to do oil or water quench on the final piece. Like you said, it's good practice, and since I end up giving away most of what I make to friends or family, knowing the actual composition is not much of an issue in my particular situation.
  9. If you're attached to new steel, read no further :laugh: but bandsaw blades are great. I have used everything from 30 year old woodcutting blades to new metalcutting ones to sawmill blades with success. They are often high nickel alloys, sometimes L6 or 15n20 from what I hear, although I never have had one analyzed. The main cautions are to grind off the teeth first to prevent cracks from starting (easier with the smaller teeth on metalcutting blades, big sawmill teeth take a long time) and (probably but I've not run into this problem so far) stay away from the fancy bimetal or high silicon blades. The nice thing is that a single blade will all be the same alloy, whatever it is, and the blades are quite long so you can get a dozen or more uniform layers from a single blade. Plus the surface is already shiny and usually pretty clean, much better than on strapping, especially if you can get the bent/dull/broken blade straight off the saw. The labor in cutting and grinding off the teeth is the main downside.
  10. I used to be a chemist...so here's what I have been able to find out. Rusting starts with iron losing 2 electrons to oxygen to form iron 2+ ions. Iron 2+ and oxygen 2- combine to form iron (II) oxide FeO which is black. The electrons react with water to form OH- ions, which also react further to make iron (III) oxide Fe2O3 which is red (hematite). To make it even more complicated, there is also iron (II,III) oxide Fe3O4 (magnetite)which is a combination of the first two. Rust is a combination of these with extra OH- attached in varying quantities, which also is what limonite (bog iron), goethite, and other iron-bearing minerals are made of. So, by manipulating the levels of oxygen, H+ (acid) and OH- (base) you can drive the reaction to favor one form or another of iron oxide. The peroxide adds oxygen ions, while salt and vinegar together make a variation of hydrochloric acid (also called muriatic acid, HCl) that adds lots of H+ and Cl- ions to the mix. All that together makes really quick rust. As someone else mentioned, the boiling keeps oxygen away from the surface and the heat promotes the change from red to black oxide. Black oxidation/rust is also characteristically formed in buried or underwater environments that lack oxygen, preserving Viking swords for our enjoyment. All in all a cool process! thanks for sharing it.
  11. mmm, mead. Wouldn't have to be a sacrifice though; maybe the quench would just warm it up for winter consumption, like the traditional hot poker in mulled wine. Worth a try.
  12. You can also take the middle junk out and replace it with a solid round bar the right size. It's that much less air space to weld up, and gives a bigger bar at the end. But if you grind too deep it will show on the surface, and will show on the point regardless (I suppose that's another argument in favor of forging close to the final shape).
  13. Wow, if you've got 25 acres to work with, all you have to do is pile up some brush and burn it, preferably right before a rainstorm. Then make a box with hardware cloth on the bottom (wire mesh with 1/4 or 1/2 inch square holes) and after the rain is done, screen out the charcoal from the sand, clay, rocks, etc. This makes nice small pieces that make a good hot fire. You can also pack a 55 gal drum full of small pieces, put the lid on with a small hole in it, and burn the brush around it for 2 or 3 hours (smoke will change color when it's ready). Let it cool overnight, and you'll have half to 2/3 of a drum full of charcoal. Bigger pieces, but less dirt than the brush pile method. You can also get lump charcoal at natural foods stores, and sometimes even at walmart, at the natural food store near me a bag is about $5. Propane is nice sometimes, charcoal others. Charcoal is a lot safer, there is a lot less to go wrong, you can see it (not just smell it) and it's not explosive either (edit) oh yeah, construction sites are a great place to get lots of scrap wood for free, but remember that the green treated lumber is poisonous when heated or burned so make sure you don't get any of it mixed in by mistake
  14. I think animal fat with rosin dissolved in it is pretty close to the recipe for 'greek fire', good stuff to fling at your enemies' ships but not too good to have catch on fire in your shop. Anyone know how long mineral oil has been around? I think it boils around 500F.
  15. INTJ here. Interesting trend.
  16. Bohning sells something called Ferr-L-Tite for attaching arrow points to a wood shaft. It may actually be some kind of pitch? Heat it up to liquid with a torch, press the parts together for a few seconds while it hardens, then it will hold up to the shock of arrow hitting target. About $3 for a thumb-sized stick.
  17. The metal foil tape they use to seal furnace ducts works pretty well. Another good fix is a tin can. Get one with the open end the size of the larger pipe, and cut a hole in the smaller end. You can cut it with a utility knife if you're careful; make the hole a bit small, and flare the edges with a ball peen. You can also cut slits and fold out the open end to make a flange to bolt the can over a square fan. Foil tape helps seal the connection if you do it that way. Better late than never, maybe this will help someone else.
  18. The US debate between AC and DC was partly the result of a feud between Westinghouse and Edison. Apparently the electric chair was part of a scheme to convince the public that AC was unsafe. Here's a link with some history: AC/DC ::
  19. Good question. I started at about 23, and still have the first thing I made, a really ugly but more or less functional rolled-socket spear point that began as a rr spike. Of course that doesn't count the years and years of geekdom I spent in D&D, then F&SF conventions, then SCA, and all those interests led me to begin smithing. I think of it as sort of a progression, from all mental toward a more healthy balance between mental and physical activity. It's now a dozen years later and I'm still learning every day, but the pieces are beginning to fall in place. And I'm having a blast.
  20. If the 'dips' you mean are like pits that are corroded into the surface, you sometimes have to remove quite a lot of metal to get through them. Don's Japanese 'water on the anvil' technique pops off a lot of scale before it can get hammered into the surface and cuts down a lot on this kind of pitting. Not sure that's what you were asking about, but it could help. And like everyone said, draw filing is a great technique. I find it helps locate quite a few arm and back muscles you probably didn't know you had
  21. I'm still at the bottom of the learning curve on presses. What sorts of differences should I look for when considering a press for forging/welding and what I see locally, which is the 2-stage horizontal/vertical log splitter at Lowe's? The only ones that jump out at me are the need for a different shaped ram end (not a point), and for some kind of anvil block underneath it. What else?
  22. Tai, in Oaxaca you can buy dried locusts in several different size ranges at the markets. Salty, crunchy, like they should be in a bowl on a bar counter. Lots of protein too. mmmm. They are a reddish color.
  23. I don't know the metallurgy yet but I'm fairly confident that I can learn it with some help (ok, maybe a lot of help ) from everyone here. Would anyone care to elaborate on chromium carbides and their care and feeding? And some questions specifically for Howard: if I did ever attempt to pattern weld it to something lower in C like 1045 (how about 1018? or is it too different?), I would expect the carbon to migrate toward equilibrium somewhere between .45 and 1.00 (would this happen before the grain got too large?) but what would the other 52100 elements do? The pieces I have are not large, so if I could get the stuff to forge weld I could do san mai or a low layer count pattern weld. Do you have to add fluorite, or is just borax a sufficient flux? Is it any easier to work with the 52100 after it's 'diluted' in layers with a lower alloy? At this point I'm mostly concerned with making a blade that is functional and adequate, as opposed to wringing every drop of hi-tech potential out of a particular alloy. That is to say, I'd rather be able to reliably get, say, 55-58 HRC and relatively durable than to occasionally hit 60+ and lose a lot of work to cracking etc. I'd like to heat treat it myself if at all possible, rather than paying someone else even if they might get slightly better results. I'd like to use a forge whenever I can in the process, because fire is fun If there is no good way around it, I'll have to use these pieces for some little stock removal blades and go with a commercial heat treater, but I'd rather not. I forsee a lot of experimentation coming up, I'd just like to minimize the dead ends by not repeating what others have already done. So, thanks all, and keep those thoughts a-comin. Michael
  24. Thanks Tom! 52100 is tricky stuff, and as I found out, it burns at just orange heat. I then made one piece that turned out ok but the second piece cracked and the tip fell off, hence my questions. The tip fell off after tempering, so I'm betting it may actually have cracked in the quench (motor oil, yuck, I'll try veggie oil next time). How hot are you going up to on the thermal cycle part? And is your quench water bath temp, boiling, or somewhere in between? I have been heating quench oil to a couple hundred degrees before quenching, but will happily try something different if anyone can suggest a more suitable procedure.
  25. The L6 thread has been really interesting. Could anyone offer some similar advice on heat treating 52100? I've got a coal/charcoal forge, a propane forge, and a kitchen oven to work with, so it's not the highest of technology. I'm hoping it will be enough though.
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