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Jerrod Miller

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Everything posted by Jerrod Miller

  1. Do they have to be soldered together? The shank will go through the "washer", then when peened it will all hold together, no?
  2. For a simple button shape that is workable, but with the file work originally present that would leave anything that floats (sand or slag) stuck in those neat crevices. I would also worry about pouring straight down onto the shank, as the sharp edge transition may erode, and that sand can go somewhere unpleasant. Lastly, if your sprue isn't quite right you are more likely to get shrink in the center of the face. Whenever possible important features (detailed faces) should be kept in the drag (bottom, pointing down) and away from gating.
  3. Another fun trick is adding some scratch vents. On the parting line just scribe the smallest line from the part to the edge of the flask. The goal is to make it easy for air to get out, but too small for metal to actually get in it. I doubt they will be needed for your setup given the open vent via the shank.
  4. Nice! Yeah, that gating system is really rough. Smoothing that out will help.
  5. Need to put some gold leaf in the numbers to make them pop now. Very cool die.
  6. I would fix everything else design-wise first. Then, if you still aren't getting the surface finish you want you can explore that. I meant to mention that you can totally hand cut the gating system into the sand, but it will be better if you can ram up the sand around a solid pattern. Cut sand surfaces are not likely to be very smooth and the sand more likely to erode out into the casting. And the sprue should be a bit taller than you want the final pin length to be. This is so you definitely have a clean surface where you cut it to length, but also to give you head pressure (cupro-static pressure, in this case) in the mold.
  7. Other than getting your sand just right, here are a few things that I would work on for the mold/molding process. I would cut the shank fairly short. Just long enough to grab it to pull the head out of the sand. This will still an impression in the cope sand that then gets drilled out, all the way out of the mold. Cut the final pin length as needed. You want the gating system much smoother in terms of metal flow. This is especially important with copper base as it really wants to make air bubbles (Al too). Below is a very quick and dirty diagram (nothing calculated). Key features: Well at the base of the tapered sprue (with integrated funnel) to smooth out flow and transition from free fall to horizontal flow. Ideally this would be parabolically tapered, not straight; but that is just overkill. Large opening to allow for faster pouring. Fill up the sprue as quickly as possible. Runner the extends beyond the ingate; it is in the drag. This is there to help flush oxides from the start of the pour and any sand that made it into the gating system to a sacrificial place, not the casting. Ingate in the cope, angled backward to the runner and tangent to the part. This will help direct the metal in the smoothest way into the part. Not show in the image is that your stud/shaft should be drilled out to the open air. This will act as a vent to let all the air out of the mold cavity as it is being filled with metal.
  8. My first ever experience with casting was an awful failure. You can certainly get there. Are you doing green sand or oil? Getting the material ratios is critical for optimal surface finish. This includes sand grain size ratios. You will also want a much smoother gating system. I'll try to return to this thread later when I have more time for more pointers.
  9. I found some of them on YouTube for free, on the Craftsman's Legacy channel. The Blacksmith: Lorelei Sims The Swordsmith: Kevin Cashen The Armor Maker: James Gillaspie Sadly, Tim's episode isn't in their "full episode" playlist.
  10. Looks like Tim's episode was Season 1, Episode 10. I created a free account at Craftsmanslegacy.com, then found out I needed a Vimeo account to watch the episode. So after creating a free account there... I do not have permission to watch that video. Not sure what is actually required to watch it. James Gillaspie. Season 2, Episode 9. Kevin Cashen is Season 4, Episode 1.
  11. @DennisKrielThat is some good looking rebound on the cast anvil. Do you get the same rebound on the assembled/welded anvils? Anvil production is a very tiny percentage of the work we do at our foundry (a couple dozen per year), and I am a big fan of more anvils being in the world, so I am happy to see more people making quality anvils. It also is very good to see manufacturers visiting the forums like this to support and back up the products. Perhaps you can end up working a deal with a place like Blacksmiths Depot to buy whole containers and become a N. American reseller for you. I hope you can continue to make and sell a bunch of quality anvils!
  12. Considering everyone said to stick with the single burner, I would say you missed out some of the discussion. This tends to not work as well as one would like/think. That was my reasoning to building a double burner for my first forge. One of the many mistakes I have made in forging.
  13. I had the same thoughts when I built my first forge. Boy was I dumb. Smaller is much better to begin with. You will never outgrow a small forge, though you may also need a larger one.
  14. I wonder if Kelly Cuppples would have anything of use for this? You'd have to email him to ask. octihunter@charter.net
  15. Broaches are generally pretty good for precision, perhaps you need a finer toothed one? You can also use a jeweler's saw (after drilling a pilot hole) to get good precision, but not very fast. There is also burning the tang in, depending on material. I'm sure you'll get plenty of other suggestions here, too.
  16. This is not what their website says (at least for the 35kg anvil, the only I saw that said anything about construction). Which is good, because casting a steel base then welding on hardenable face is not a very wise way to go about things. Their 40kg anvil clearly has feet welded on, which is an odd choice when casting. The face there looks like it could be welded as well. All and all, it seems a bit sketchy to me, and a lot of money to sink into something which would have virtually zero recourse if things went sideways. Then again, I'm biased and anvil rich.
  17. Not for wrought. The etch will attack the iron and the impurities (slag) differently enough to show the pattern.
  18. Let's try to keep this kind of negativity to a minimum.
  19. Air or room temp means just what it sounds like. In your case here, 70 degrees. Whether cooling to room temperature is significantly better than just going to black is debatable. As long as it is truly black (as in black in zero light, not in mid-day sunlight), so about 900F tops, I think that is generally good enough.
  20. Be warned that this is against what ASM recommends. ASM favors part survival more than optimum hardness though.
  21. The Heat Treater's Guide says to air cool from 1695-1795, temper at 300-320, cold treat at -120, then temper immediately after reaching room temp. I think the main reason anyone would/should use A2 is because it is pretty easy to HT with a controlled oven and get pretty good dimensional stability with good hardness. So mainly people making steel dies. I don't think it is especially good for blades, but it isn't horrible, either.
  22. I've been thinking about this one since I saw it this morning. I have used quartz structures to house metal in and flow Ar, N, or CO2 through for annealing cycles and such. In this case it was a matter of a tube shaped oven (much like a propane forge in geometry) with a much longer quartz tube running through it. Push the metal to the middle, plug both ends with a little refractory wool with a rubber tube in and a tube out, and purge gas through the quartz tube (putting the outlet rubber tube in a bucket of water lets you watch the bubbles to ensure your gas is still going through the system). Whenever I have done carburizing I have used the "seal it in a canister packed with a bunch of graphite" version (AKA Pack Carburizing), not gas. Gas carburization utilizes atmospheres that are both toxic and highly inflammable. When combined with air (oxygen) this can lead to explosions. The closest I have ever wanted to get to this is actually just running a rather rich furnace environment in a gas-fired furnace. I have tried adding a bunch of charcoal (not very effective). Industrial heat treat ovens generally run fairly oxidizing (like 30% excess air), so I have always wanted to add one more burner near the parts that burns fairly "inefficiently" (i.e. very rich, possibly just gas added, no air) to shroud the parts in a rich environment and have the excess air from the other burners finish the combustion of that gas. My goal in this would be to reduce or even eliminate oxidation/scale, not carburization. My recommendation would be to talk to furnace manufacturers to see what they would recommend for equipment to either modify current ovens or to possibly buy a new (at least to you) oven for your trials.
  23. I may be a little crazy, but it is good to have other people back up that I'm not that crazy. At least in this one aspect.
  24. In addition to what has already been said, here is what I would add. Start with aluminum. Far less likely to have bad contaminants that will cause bad fumes. The cooler temps help while learning, too. buying some pure tin can be a little expensive, but a MUCH colder melt and pour temp might be good for learning purposes. Personally I wouldn't worry nearly as much about lead as I would zinc. Like an order of magnitude or two more. In my experience zinc fumes are much more likely to be coming out at harmful levels. Always have a full plan put together before you start to melt. This should include where every bit of metal is going to be at all times in any scenario. What if you melt more than the mold can take (this should happen 100% of the time)? Better have pig molds ready. What if you start getting a leaky crucible? Better have a safe place to put it (sand box and pig molds). What happens if the mold leaks (sand bed around the mold). Winging it is not a good plan when liquid metal is involved. I'm going to emphasize the need for a face shield, all natural materials for clothes (plastic/nylon + liquid metal = melted to the skin and then possibly on fire), no exposed skin. Free water is a major hazard. Beware.
  25. vlegski beat me to what I was going to say, soak if for longer than you think you'd need to before you work it. It really needs to be pretty hot all the way through. Also, small movements (as a percentage) between heats while it is so thick.
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