We built a homebuilt Bearhawk airplane. The Tinman tech welders are used by home builders but the Smith AW1A torch that has a selection of nozzles is a good choice as well. One partner who is a welder used to using TIG welders for similar work. He did a lot of research on torches and settled on the Smith AW1A airline torch. They are light and very capable due to a good selection of tips for different thicknesses. We found a Smith AW1A torch with some tips at work & we able to get it cheap as it was no longer used. My friend was doing beautiful welds with the Smith torch that was similar to what he could do with a TIG torch. We did bend tests and tried to break the welds but they stood up with no issues. He did a lot of very nice fine welds with the gas torch but we caved and bought a Lincoln 225 precision TIG for the fuselage and tanks. I have seen videos where the person was oxy acetylene welding body panels with the Smith torch and looked to be doing quality work. Smith torches can be found for a reasonable dollar and may be a viable option to consider. I get by with MIG so I am just sharing what I have learned building an airplane and watching my friend TIG and gas weld.
Some of my early Dillon (a.k.a. Henrob etc.) work. 0,8mm steel, used filler where I had to, just fused the edges together where I had a tight enough fit - the center seam looks like no filler was used. I had a few hours of practice before I did this, no previous welding experience (unless you count five fluxcore spot welds).
I remember the Airframe/Powerplant inspector coming to friend Jeffrey's shop, spying the mIg setup, asking if the airframe tubing was Oxy-Acet welded. Jeff said yes, it was... A&P man said "It better had..."
Found my Cobra last summer. Forgot I had it. Since I got the Meco Midget it's all I use on sheet metal. I could never get use to the Cobra. Just isn't comfortable to me. To each his own I guess.
Beside the fact that welding aircraft fuselage tubing with a MIG looks messier, the inspector told us, that although using the MIG would be acceptable, he stated that the joints could be left stressed when welded by an inexperienced welder. His preference was, to see them welded with TIG or Oxy/acetyline. When welded using the MIG, the clusters can still be stress relieved by heating to stress relieve them after the MIG welding. Back when I was involved with homebuilts, a lot of engine mounts were MIG welded. A previous poster discussed the weight of the Dillon/ Henrob/Cobra torch, and I readily agree with his observation, but because of the more comfortable position of the wrist, I found that once I was used to the torch, the weight became negligible. Another thing I should mention regarding this torch, is that in some situations, the fact that the hand is positioned closer to the weld can be inconvenient. There was a heat shield supplied with the torch to overcome this problem, but it is a little bulky. I also found that when working in tight places, such as working between the body and the top of an exhaust tube being welded, using this torch can be a pita. For this situation, I use the aircraft torch. My failing is, that I am like a crab. Once I have acquired a tool and learned to work with it, I end up liking them so much that I can't part with them anyway. Bob The little guy in the middle is my favourite when I am not using the Cobra. It has 6 welding tips, and the little cutting attachment.
An instrument specifically made for brazing is a gas brazing torch. It uses a variety of fuels, including propane, acetylene, and natural gas. It can also control the flame and use a variety of tips to achieve good results on a variety of materials. A brazing torch that uses air acetylene can also be an excellent alternative for brazing and soldering. However, because it can only generate about 2700 degrees Fahrenheit, this gadget is only advised for tasks requiring less heat.
Brazed bicycle frames have been quite common, and there are plenty of brazed motorcycle frames out there too. I believe Lotus(?) brazed some car frames too.
Many British race car chassis were brazed, including the Ferguson NOVI awd race car. And as stated before, bicycle frames used to be silver brazed, and some of them still in use after 100 years are still going strong. Having said that, I'm not going to build one that way.
A vote for Meco on sheet metal, especially crappy old Model A steel. I personally have not had any luck with Henrob. But I didn't practice much. The Meco came naturally.
Here's my Oxy-Fuel torch selection. The red Marquet was my fav for the longest time. Just can't get it to work any more. Can't find parts to overhaul the torch body or just keep a steady flame. What a shame it was a light weight, welders dream. It was from their "Aircraft" torch set. Now I use my Smiths AW 1A. 0 and 00 Tips. I bet it's an "Aircraft" line of touches as well. Top is a Victor 100C torch I teach at a college with these. Tip 0 & 00 are about $50.00 each. They work well. I bet all these torches I've shown are from the "Aircraft" line of torch sets these equipment company's sell. Last 2 pix are from a visit to Terry Hagmenn's shop in CA. (I hope I spelled hi name correctly..what a true craftsman) It is a "Jewelers" torch. I have a friend that recently had defibrillator installed as well. He found the information regarding TIG-MIG-ARC welding extremity confusing. He was welding with an old Miller 300 transformer style welder and Miller Matic 35. He asked his Dr. to put a monitor on him as was working in his fab shop welding grinding and so on. They found no issues with High Freq and other electronic "noise" in the shop. I might suggest you check with your cardiologist as well. He has since upgraded to Mller "Inverter" type MIG/MAG and TIG welders. good luck, NaCifan
So what ever became of this? As much as I read here I dont read everything. That Cobra was indeed impressive. I forgot about those, stuck in my ways. Seems a good place to bring it up, but back doing my racer fab thing I was told monster trucks were moly, but some things mig welded and all the others tig with mild steel wire because they broke shit so easy with moly wire due to the nature of their use. Can anyone confirm, or ever heard such? I did some redneck testing. Tigged a tube with moly wire, and one with mild. I set up the joint to blast it with a sledge hammer, the moly cracked and pulled some tube away. The mild took 2 hits and tore the side of the tube pretty close to the weld. I'm not the best ever born weldor but confident that my shit is safe. I quit using moly wire after that. Most say I'm a hack for it. And yes indeed this is from the zombie thread dept but WTH.
Douglas Dam 1942. Called into service, if your average house wife can so can you. Notice she bent the end of the wire, safety first. Which brings us to where we are today, electro-magnetic fields, high frequency fields, 5G, cell phone radiation and modern pacemaker tech that no one is willing to say is safe to be around when you weld. Did the magnet have an effect? Regarding the torch set. Might I suggest you do a practice run on a similar to frame thickness material. You'll need a big tip, not a small one. You'll be better off using a GMAW to tack it together. About brazing...while not if you want to fusion weld over it. But as far as strength goes, just like a weld with another process, it to can be incorrectly applied which affects the out come. The conversation went around to materials and the use of "Chrome Moly". Well a reason to braze over a fusion weld would be less impact on metallurgical effect to the material. But the other reason is, some are not as skilled at controlling the welding and that has an effect on those properties. There are codes that govern best practices, but not when it comes to building in the garage. But it is a forgiving and forgetful world. You do not want to gas weld it is my opinion. SMAW, or GMAW is your better option. I am not a doctor.
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