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Michael Stuart

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Everything posted by Michael Stuart

  1. Well, I tried my first bloomery run but got no iron for my troubles. I'm pretty sure I used too little charcoal, and I know the tuyere got partly plugged with slag at some point. What I did get was many pounds of some really dense material that I think is slag saturated with dissolved iron. It's dark greenish black and heavy like iron but grinds to a slightly shiny black surface, no silvery iron shininess in it at all. Other parts of the stuff look a lot like a bloom but aren't. Each part just shatters under the hammer no matter how hot I get it. It is somewhat magnetic so that must be where all the ore went. I'm guessing I should use this in place of flux when I get the bloomery rebuilt and try another run. The stuff I produced stuck to the inside wall pretty well on the side above the air supply. I had to knock over the stack and bust out the bottom, hitting the stuff with a big iron bar from both ends to break it off where it stuck to the inside lining. Any tips or helpful feedback appreciated. Here's more specifics. Materials were about 40 lbs of mill scale (thanks Wayne!), about 50 lbs charcoal. I started the heat with a blown wood fire inside, and when this burned down I filled up the rest of the way with charcoal. The stack was cylindrical, about 14 inches ID and about 30 inches tall. It insulated well and didn't break down much with the heat although a couple fissures vented smoke by the end. I patched these with mud which fired to a nice brick red color. The air was supplied by a blower reducing into a 1 inch diameter hole about 7 inches above the bottom. It took about an hour to preheat, then about 6 hours more to run. At the end of the run, I found the bottom inside (below the air inlet) was nearly empty, with a big shelf of the black stuff glowing bright orange, attached to the wall above the air inlet and extending more than half the diameter of the stack. No sign of the mill scale, which is why I'm thinking it must have dissolved into the slag. Not much charcoal left either by the time the last 6-8 inches of it burned down inside. Backing up to the beginning, as the charcoal charge burned down, I started alternating charcoal/scale/flux charges, poking into the top foot or so with a pointy bar as needed so it would pack down. Each charge was about 3 lbs charcoal but I think I overshot and added more like close to twice that much scale, plus a small handful each of limestone powder and sandbox sand. Next run I'll go back to 1:1 charcoal/ore and will get a scale to weigh it. Some of my charcoal was hardwood (oak/hickory) in big pieces, while about half was much smaller and mostly sweetgum. The smaller stuff was too small, and the air didn't get through it like I think it should have. The other stuff was too big. By the time it finally occurred to me to mix the two, I was 2/3 done. I've got lots of ideas how to make the next run better, and with any luck even to produce some iron. But still, as a day playing with intense fire it was great fun. I've got the missing arm hair to prove it. Michael Matthews
  2. Thanks again Jesse. I think I understand the process, but I need to get the book you mention and do some more reading before I'll be able to get all the terms correct. Just one more question for you and Mike for right now (hope I'm getting the chemistry right off the top of my head). I believe if I add CaCO3 in small particle size (sand to powder range I think?), the heat drives off the CO2 and what's left in the slag is CaO. If this is correct, does this liberated CO2 do something beneficial or is only the CaO in the slag the important part? Perhaps it initially comes off as CO and helps reduce the iron oxide? Would it make a difference if I used CaO (lime) or Ca(OH)2 (slaked lime) for this purpose instead of CaCO3 (calcium carbonate, limestone or oyster shell)? I'll probably go with the calcium carbonate but I was curious whether the other forms of calcium might also work. Michael
  3. Thanks Jesse, I was thinking I probably would go with calcium rather than sand. Some of my charcoal is gathered from brush fires, and probably has a bit of naturally scraped up sand in it as well. I think I'll build a wood fire for preheat, then add a blower as it turns to charcoal. Something constructive to do with all the pine cones and small branches the trees keep dropping in the dirt that I call a back yard Do you fill all the way to the top with charcoal and then add the first charge as it burns down? I missed the very beginning of the tatara at Harley's but I think I understood that was how they began. I am aiming for wrought iron and not steel with this set up but if I understand correctly, it's mostly the height of the stack that makes the difference in product. I'll try to get some good photos to share once I finally get started. Thanks again, Michael (Matthews...there seem to be quite a few Mikes and Michaels around)
  4. Jesse, what was your preheat time and run time on the cob model? That's a very cool photo by the way. How long a preheat would you suggest if using only wood/charcoal and a blower? Does the cob get hot to the touch on the outside at any point? I've constructed one about the same size/shape as your cob model and am intending to try a first run using hammer scale as the ore source. Just wondering how much time I should estimate for an entire run and what else to expect. Thanks, Michael
  5. Here's one of Alan demonstrating engraving by putting the runes for 'mjollnir' on the side of my diagonal pein hammer, a special thanks also to Jake for writing the runes: and a big whopper piece of rebar heating in Chris Price's washtub forge, with a little help from a propane weed burner (just visible at the right side): There are lots of photos posted by several folks over at the Outpost forum for those who may wish to see more. As everyone has noted, it was an amazing weekend. Sensory overload, in fact. Thanks to all and especially to Larry Harley. Michael
  6. Nice work Jesus. I enjoyed meeting you at Harley's, hope I have more chance to talk and look at your work next year. Michael
  7. Mike, I hate to disagree, but borax is sodium tetraborate decahydrate, at least that's what my box of 20 mule team says. So it may produce some sodium flare. Of course I have no idea what safety glasses this fact may require, just wanted to point it out for accuracy's sake. Michael
  8. mmm, homebrew mmm, especially mead. I think I have a bottle on reserve to bring to Harley's again this year. Will be seven years old, older than my either of my kids. If I find I still have two bottles left, I'll bring the drinking horn (it holds two). and back on the tobacco topic... not that I want to hear if any of you have tried it--really--but I recall reading this book about tobacco shamanism in South America...apparently tobacco enemas were not uncommon...now there's a buzz Michael
  9. Cool! I used to have a 1/2-220 on my grinder but since moving I only have 120v in my shop so I'm down to a 1/3 hp at 120v and it really is barely adequate. 2hp must be really nice. Michael
  10. now all you need are some grits...
  11. Interesting topic Brian. For me, respect for Don and his knowledge and philosophy go a long way. Plus it's immediately obvious that the level of expertise around here is tremendous, which is not the case on many other sites. I post elsewhere fairly regularly when I believe I have a useful contribution to make to a discussion, but here I find I read a lot more often than I write. Soon I hope to be capable of making a blade nice enough to share here. BTW thank you Don. Michael
  12. It looks Persian-influenced, maybe Mediterranean too, still I don't know what I would call it except 'beautiful work.'
  13. pre-1982 US pennies were 'solid' copper (maybe a high-copper alloy?), since then they have been a zinc core with a thin copper skin. The newer ones will melt and fall apart under flame from a propane plumbing torch. A chemistry geek trick: make a small scratch on the edge of a newer penny and soak it in dilute hydrochloric acid for a couple days. The acid will dissolve the zinc center but leave the copper skin. If you do it just right, the skin will fill with the hydrogen bubbles liberated by the reaction, and the penny will look the same but will begin to float.
  14. Beautiful work! I found some neat tables online here: http://www.copper.org/resourc....bs.html Looks like your Cu/Ni/Zn alloy is what is here called nickel silver (sometimes also called German silver I think). Funny name since it doesn't have any silver in it, I suppose it looks like silver though. Michael
  15. I posted this on SFI's classifieds also but no one seems to be interested over there. Vulcan, made 1943, weighs 131 on my bathroom scale but I'm conservatively guessing and pricing based on 125 lbs. 1 inch hardie and 1/2 inch pritchel. Good condition, square edges, no repairs apparent. Face is 12 1/2 inches long. I'm asking $2 per pound or $250 if picked up in Durham NC or I'll consider shipping it at buyer's expense.
  16. Michael Stuart

    anvils

    I probably wouldn't mess with it unless they are in the way somehow. My PW has the same issue, on the old wrought-body anvils the wrought is soft enough to move over the 50 or 100 years of pounding they have taken, so the steel top plate slumps over. The slumped part makes a good wide curve when you want a smaller radius than on the horn, or if you need to pound harder while still having the body of the anvil underneath the blows. I think the Fisher co. used the slumping in their ads to say that their cast iron/steel face process anvils were superior to the wrought body ones, since the cast iron ones do not do this. But few folks today would prefer a Fisher to a Peter Wright.
  17. Speaking personally, I'd be disappointed to see someone using a propane forge at a ren fair But I like the 'knife board' idea, or maybe a series of small pass-around sized boards with a before and after piece for each operation. Then the audience could look at what you are intending to do as you are doing it, and you won't lose as much time waiting for the piece to come back in as you would by passing the actual piece around. A water quench steel sounds like a good plan too.
  18. A somewhat educated guess on the tiller tines is that they are a medium- to high-carbon alloy with extra silicon and some other stuff ??? probably manganese??? I tried some of these and had a bit of trouble figuring out a good heat treat, but that was several years ago and I haven't had any to play with since. One other note, if these are the 'heavy-duty' ones from Troy Bilt there may be some hard facing material left on them; grind it off before trying to forge them.
  19. Anyone try a metal mailbox? Flat bottom to put a brick to catch flux, curved top to hold kaowool in place, front door opens to put the wool in, and only 8 bucks at home despot.
  20. If I was in the market I'd talk to John Larson who posts over at the keenjunk site. He has put an awful lot of work into designing his hammers and has always been willing to share what he has learned. Here's a link to a pic he posted of one: http://www.keenjunk.com/sketchbk/jl30418.htm I think he's located in Pennsylvania, could be wrong though.
  21. Don, did you taper that (axle) by hand? Nice either way, just curious. Chris (Prizzim) showed me a neat stake anvil design at Harley's hammerin. He notched near the pointy end of a splitting wedge and drew out the end from the notch (similar to a stick tang) so the stake has shoulders to keep it from splitting the log or going in too deep to get out.
  22. I haven't found a pet store bone the size/shape I want, but it seems with other 'found' bones like they want to splinter or split where a hole is drilled. I have a couple of bone scales I want to use at some point, but I don't want them to split so I haven't done anything with them yet. So for a 1/8 inch or so pin hole, what drill speed would you recommend, faster, slower, doesn't matter? I've got a drill press with 9 speeds, although I usually leave it on the slowest setting since I mostly am drilling metal.
  23. 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.
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