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I Forge Iron

Andy98

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  1. For anyone interested, this is the 3/4" version running with the PC fan at full (the last batch of videos were the 1/2" version). I don't think I can run the PC fan less than about 70-80% and still maintain the necessary output velocity. I believe the 3/4" works better.
  2. Wayne, Buzzkill and Frosty I see I have argued and speculated you all past your tolerance levels (not to mention having hijacked the thread). I do totally accept the stated benefits of ribbon burners and although I see that my first post here does read a lot like I was rejecting that information. It does also make intuitive sense to me - at least I did say that somewhere above. ...but I do also want to understand the mechanics of why they are better. I don't see that as a bad thing, and I don't apologize for that. I realize that some people find theoretical discussions annoying, an
  3. Hi - In both cases the burners are required to operate with the gas/air velocity at the nozzle exit being at least the flame propagation speed. That means that a single-large-burner running at the minimum will have the gas/air exiting at the same total (stagnation) pressure as the many-small-nozzles also operating at it's minimum. The fact that the small nozzles are diffusing the flame is probably important. It's also possible that the many-small-nozzles allow ribbon burners to run closer to their minimum? For all I know my burner is dumping fuel/air into the forge at several times f
  4. Hi - Thanks! I saw your post in the other thread with the actual fuel consumption estimations too. Interesting stuff.
  5. Is it your belief that the dragon's breath is caused by gas that didn't have enough time to burn in the forge? I always assumed it was completely caused by fuel that didn't have enough oxygen inside the forge, and thus burned on exit into the atmosphere. I think this is the real reason. If you think of the "surface area" of the flame itself, lots of little flames will have more surface area than one big jet. So I think the gas at the centre of a small jet will both slow down more quickly, and heat up faster, thus burn sooner. Total guess. If your belief about dragon's breath being
  6. All I know is what's in the video. He uses a thick wood board placed on his anvil, and just for the initial setting blows. Second heat onward are directly on the anvil or powerhammer. He was using it for welding an oddly shaped billet made up of many pieces of cable, hence my initial assumption it was for stability. But he also does it when setting the welds on more uniform billets as well. Most of the comments on the video are in, I think, Russian - so I couldn't gleen anything there (admittedly I didn't try that hard). I might comment and see if he replies.
  7. I think that is the autoignition temperature, not the flame temperature. Per this link the flame temperature in the "continuous" part of the flame is around 1500F and Wikipedia states it as ~1800F. So not welding heats, but surely hot enough to significantly reduce the rate of cooling. Combined with the insulation effect of the wood, and the helpful pressure distribution the wood would give when you land the tacking blows, that seems useful...
  8. I'm confused by this. Why would the flame speed be any slower? Ribbon or not, burners generally run with the gas/air mix exit velocity at close to the flame propagation speed. No? I'm also not clear why people believe ribbon burners will waste less heat. I'm not saying the do or don't (especially since I've never even seen a ribbon burner in person) but if I input X cfm of unburned gas/air it'll produce Y cfm of exhaust gas, and thus the same exhaust flow velocity regardless of wheather that input was via a single nozzle or a ribbon, right? So unless the ribbon burner is actually running
  9. Are you judging efficiency just by psi? That doesn't tell you the full picture. You need to know flowrate (by mass or volume). Your low-input-pressure burner might have a big orifus and thus still be delivering a high volume of gas.
  10. Hi, continuing my practice of vicarious blacksmithing, I came across,this video: In the video, the blacksmith sets the initial weld with the workpeice resting on a wood block (happens in the first minute). I assumed this was for stability, but thinking about it more (while watching Mark Aspery's scarf welding videos) it occured to me that the wood would also help insulate the work piece from the heat-stealing anvil. Further, since that wood is burning it might actually heat the metal and reduce oxidization. Is that a crazy thought? Has anyone ever seen this approach b
  11. I couldn't find this posted here before, so I thought I'd post it up. From Lewis Razors: He has a build video too, the most interesting step of which is hammering the brass (copper?) tube to narrow the ID sufficiently to hold the mig tip. Cheers.
  12. Exciting updates: I tried a few new configurations: 3/4" burner, fan attached to the "drop" of the T, natural gas attached to the "run" of the T. Air-rated stop valve added inline with shutoff ball-valve. 1/2" burner, gas via the "run" and air via the "drop" 1/2" burner: 3/4" to 1/2" reducing T, 1/2" mixing tube approx 4" long, air into the 3/4" run, and NG via stop-valve through the "drop" of the T. Results: All 3 are successful! In all 3 cases I could turn the burner up high enough to make it stutter a bit, but it never burned in the mixing tube. Hav
  13. Ok, so I got a chance to run the thing again yesterday. Now that I have a better idea what I'm looking for, it was easier to recognize what was going on. Here is how it's behaving: State 1: Hot forge Gas set low. I set the fan at 100% Result: I can get a good roaring burn with no visible dragon's breath (to me, in dim-ish daylight). State 2: From State 1, I increase the gas: As the gas quantity increases, the flame goes from roaring, to sputtering, to (I believe) burning in the mixing tube. Result: The mixing tube gets hot. The burner
  14. Yes - that's what I was getting at with the momentum thing. I'm picturing that pressure wave going backwards to the PC fan. I figure for lots of reasons (momentum, flex, etc..) that PC fan will be less capable of keeping the air pressure steady than a bigger blower. Plus, I figure that the more pressurized air (e.g., in the supply duct) the more the pressure drop would be diluted. Kinda like a pulse jet effect. Anyway, half the time when I think about this it makes sense, and the other half of the time it seems crazy.
  15. Apologies if it appears I have ignored this advice. I haven't - I have been looking into it quite a bit, trying to see if I can find a good and reasonably priced option. I assumed, perhaps incorrectly, that the recommendation to go a needle or globe valve was to help me adjust the flow more easily and not because it would actually meter or regulate the gas flow any better (once set) than the ball valve. I've assumed it I actually want any improvement in regulation, I'd need an actual regulator. Do I have this wrong? All the fuel gas needle and gate valves I can find are in the $30+ r
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