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Dan Hertzson

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  1. If your plane was put into an air conditioned room the associated humidity levels can be pretty low, leading to wood shrinkage. Of course not as badly as wintering in a space that has central heat and no humidification, but it can certainly affect the wood.
  2. Not to be overly pedantic, but for accurate temperature readings using a thermocouple, not only does the indicator have to be matched to the thermocouple, the wires between the indicator and thermocouple have to match as well.
  3. In the last video you appear to be getting decent flame out of your burner, but a little rich. You have found the highest output you can get from the burner, but the forge may not tolerate it until it gets up to temperature. Till you get there, to keep a stable flame, you may need to turn down both the gas and air a bit more. Once the forge heats up the burn pattern will change as the flame front burns back faster to the block. You may still need to adjust the number and layout of your burner ports, as the diffuser does not appear to be effective at getting a full spread of flame (see earlier videos). This last can be done by first blocking ports temporarily with ceramic blanket, and testing. After flame pattern improves you can mortar closed any holes with high temperature refractory cement. I would consider starting by blocking the holes closest to the pipe connection if you want a more spread flame, or on the perimeter if you want a more concentrated one. The real question is why isn't your forge getting hot with this much burner feeding it. How long have you been leaving it running to see if it starts to get hot? Is your forge fully cast, or a layer of ceramic blanket first? What material did you use for casting (lightweight castable refractory or heavy)? A lot of thermal mass could take a long while to get up to heat.
  4. Actually Bolos come in a very wide range of shapes. Many of them do not have a trailing point.
  5. Looks a bit video game inspired to me. Strongly recommend that even if you don't have any knife making skills you consider mocking your design up in plywood (or even cardboard) to see how it feels in the hand and even balances. Between the cost of material, cost for heat treatment and cost of construction, this is not going to be an inexpensive design to produce. You will want to be sure you get it right before spending the big bucks. Your later drawings show the handle as being full tang, but the earlier ones have a threaded pommel. The handle construction is also a little confusing. Do you mean larger diameter rubber sections alternating with G-10 spacers? If full tang, how do these go on over the pommel? If threaded pommel the transition point between the tang and pommel seems a point of weakness. The front hole is also a fairly major stock reduction right at what needs to be the strongest part of the knife. Might want to reconsider that. I'd probably class this as a bolo, like this one from Gerber: Good luck in finding someone who can help fulfill your dreams.
  6. He has both a burner block with holes and an upstream diffuser. I've run multiport burners with no elbows upstream of the mixing point, but it does help to have a proper mixing chamber. Turbulence can help with mixing, but a better option is to put the gas connection in perpendicular to flow from the fan and keep the fan inline (as I previously mentioned). The final 45 deg elbow you have here should be no problem, but at least try switching the fan and gas ports on the Tee fitting. If you keep your fan scroll down you will maximize its capacity. Still not an optimal fan selection, but it will likely work a "normal sized" bladesmith's forge of between 300 and 500 cubic inches interior. You also still need to bake off the steam from your refractory. Run it at first with then doors open till it stops steaming, then close them down iteratively till you have a stable, fully developed, flame. Then you need to learn to avoid pop-back when you turn things down from high to low fire.
  7. Sounds like you need more blower as well. I saw that you removed some of the elbows, but did you switch the locations of the gas port and blower connection at the main TEE?
  8. Hi, Regulator should be good. I would make the following changes if you still feel you have insufficient air: Get rid of the mig tip in the gas train. Those are really only useful for accelerating the gas stream to entrain air in a naturally aspirated burner and are not needed in a forced air burner. Swap the blower and gas connections at the mixing TEE and don't reduce the duct size between the blower and burner outlet. Both side inlet tee connections and smaller duct add to duct friction, which reduces the blower effective airflow. If burner ran well, exactly as currently configured, outside the forge and is a problem inside it may be that the forge or burner block is still outgassing as it comes up to higher temperatures. If you are still driving off steam from your refractory castings it can have a significant effect. Try to slowly heat the chamber till you get up to a good forging temperature. May take some hours. Good luck.
  9. Don't have time to look through the whole string, so I'll just add a couple of notes here: Realize that by designing and constructing your own forges you will need to experiment to achieve acceptable performance. Even a small change from a vetted design can have a big impact. If you are trying to get more static pressure at the ribbon burner outlet, dropping the mixing chamber diameter is the wrong way to go. A smaller diameter duct will lead to more static pressure loss due to friction, and consequently less pressure at the outlet. Of course you are really looking to increase the flowrate of the air/gas mixture, but the pressure differential is what drives the flowrate. If you have any kind of orifice (mig tip...) restricting the gas outlet into the mixing tube, get rid of it. The connection size for the gas should be at least 1/4" diameter and possibly larger. Mostly depends on the pressure you are using for propane. This is also why indicating pressure for a forced air burner really isn't a good measure of how efficient your forge is. Also, use a variable pressure regulator capable of at least 30 PSI outlet to meter your propane source. If you still have trouble getting a neutral flame from your burner (and it is reducing), your system may be starved for air. Before switching your blower, decrease the length of mixing tube and remove elbows in the line. Short and smooth tubing will loose less pressure to friction and give you better flow. Baffles will also greatly impede flow. Flame retention at the burner outlet will improve as the forge gets hotter. Tune your burner inside the forge. Note that tuning may include either blocking off some burner outlets or drilling them out to larger diameter. This can help balance the flame locations or help with stability. Make sure all volatiles are completely burned off from the forge body and burner before firing the burner if possible.
  10. Thank you for the information. I have already had a $500 offer. But I am holding out for $600. I might try contacting the people you said. Thanks again, Kevin.

  11. Sodus NY is pretty close to me. We have a branch of ABANA (the New York State Designer Blacksmiths - NYSDB) that meets just west of Rochester once a month. This is the Genesee chapter. Your anvil is a good size and in decent condition. It all depends on how quickly you want to sell it, but priced in the $300-$500 range it should sell reasonably well. You could contact the NYSDB forgemaster and ask them to send out a notification and see if there is any interest: https://nysdb.org/
  12. Strongly recommend a sub-critical anneal (stress relief) pass at around 1,200 deg. F (just barely showing red in a dark room) before you go to harden this one. Also try to get it back between the clamped boards after it cools below around 800 deg. F after quenching (and before it hits 450 deg. F). An assistant is nice to have around to help with the latter. How are you planning on tempering the blade after your quench?
  13. As Alan mentioned, working that size piece without either a power hammer or press is going to be a struggle. Wrought, properly heated to screaming yellow heat, actually works down easier than even mild steel, but you need a heavy hammer to project down through that kind of thickness. Yes I know a lot of folks theorize that it is all about kinetic energy, and swing velocity is the primary variable (kinetic energy as a function of velocity squared). My counter to that is just try to break down a 2" round of any type of steel with a 1 LB hammer and a 4 1/2 LB hammer. I don't care how fast you swing the former, you just aren't going to get far, and the latter will make a significant impression. My theory is that hammer momentum is actually what we should be considering, and for that hammer mass and velocity are equally important. Bottom line is I recommend you heat it hot and soak it till it is heated through. Then get a buddy to strike for you with at least an 8 LB sledge... Nothing wrong with a Japanese style, forward weighted, forging hammer. You just need to use a large enough one. If not, perhaps you can send it out to someone with a power hammer for initial processing. If it is good, knarly wrought, you might find someone who can help you for a portion of the stock.
  14. 1 Other options: glued twine wrap and very thin leather over the cord. In future I wouldn't recommend piecing a wooden handle like that on a functional sword. You would be better served chiseling a lengthwise groove in two pieces of wood, gluing together over the tang and wrapping as above. 2. You are going to have a lot of trouble keeping the 5' thin blade from warping when heat treating. You will have to quench it all at once to properly harden it, and then you have to figure a way to temper it as well. This is one of the issues with jumping quickly up to making swords: lack of decent heat treating facilities.
  15. I think that daggers have been made with a large variety of guard sizes and styles over the centuries. Not sure that there is any sort of universally accepted standard, which is why your question is tough to answer. Peter Johnsson has some very interesting theories on proportions for swords and daggers, so researching his ideas may be fruitful: https://www.youtube.com/watch?v=geZ_lIsZD_E
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