TFF
Well-Known Member
You get admonished at Oshkosh if you make the torch pop because it erodes the tip. I would say in an emergency fuel off first. Non emergency, however you want.
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Upgrade NowIn 1988 I bought a few tools at a yard sale and asked the old guy if he had any more stuff he wanted to get rid of ? He said yeah he had his dad‘s tourch, but he thought it was pretty old andOne of my weird interests was to look at the hydro date of all of my O2 bottles when exchanged to see how old they were.
Kind of amazing how old some of them are. Wasn't uncommon (as of 15 years ago) to get bottles with the first stamp in the 1800's.
All of mine are half full - and out of date.
Makes me question what I have. Bet the gas bottle is very old. Replace the oxygen bottle a couple years ago. Can't remember the gas.In 1988 I bought a few tools at a yard sale and asked the old guy if he had any more stuff he wanted to get rid of ? He said yeah he had his dad‘s tourch, but he thought it was pretty old and
he told me that he’s pretty sure the bottles hadn’t been filled since before the war.
I was thinking the Vietnam war, since it was my war . Now I thought that was pretty old so I set them bottles in the back of the shop and didn’t think anymore about it till one day I came out and my son was using them. I was amazed that both the oxygen and the acetylene worked , Then when I took them in to get refilled, I asked the guy if he could tell when they were last filled.
He looked at them and kind of quizzically asked me if there was any chance that they were last filled in 1928 !
Guess I was thinking the wrong war !
I was taught to turn off the Acetylene first, to blow out the flame with oxygen. A lot less smoke also.You sure about that?
BJC
There is one thing that I haven't heard mentioned!, always shut off the oxygen first
and also install a backflow preventer between your torch and the acetylene hose. If your kit didn't come with one it's worth a special trip to the welding store.
I witnessed a shop fire when the 'O' rings in an old torch failed and a friend came running out of the shop yelling, "Run, it's going to blow!" Sure enough he was cutting, had shut off the wrong gas first, the torch snapped, the oxygen went through/around the 'O' rings and ran up the acetylene hose, carrying a fire front with it.
That is a new one on me, and I teach OA at OSH. I understood that we get ash in the torch from turning off fuel first, which makes the torch pop more over time.You get admonished at Oshkosh if you make the torch pop because it erodes the tip.
In an emergency, I too was taught cut fuel first.I would say in an emergency fuel off first. Non emergency, however you want.
I'm counting on that...OA can look horrible and be good
Hi there,I have a question about O/A welding equipment. I have a Victor torch set with an oxygen and acetylene bottles. I have always used it for cutting only. I have a Lincoln 225 for my welding needs. The first question, is there an appropriate size handle for welding. My handle with a welding tip seems very large and somewhat heavy. I have seen the small torches HVAC and plumbers use to solder and that looks like a nice size to get into tight spaces. Will it work? I assume changing to my larger bottles for welding convenience.
Second question, is can I substitute propane for acetylene when welding? When I got my torch set, I was just a poor new college graduate with a new wife and a child. I could not afford both an oxygen and acetylene bottle so used propane to cut. It was a little slower but worked. Would it impact welding?
Last question, someone suggested one of the Sport Air Workshops to get started. Will it provide enough hands on to feel confident to practice at home and be successful.
Thank you all with far more experience in this aircraft welding world.
Jeff
MIG can look good and have no penetration. One time I dropped a piece of steel that weighed about 400 lbs from about 250' up in the boiler building due to about 4' of a heavy weld that was welded in a fab shop with MIG with no penetration except for one place the penetration was about the size of an aspirin. Painted over and looked good. Very fortunate that no one was hurt or killed.Fascinating stuff re: choices on welding with other than TIG and OA, as well as leaving stuff out the designer wanted left in...
From the 2022 Bearhawk LSA accident... freshly released NTSB report.
The pilot built the airplane from plans, and its primary fuselage structure was made of tubular steel covered in fabric. He used an unapproved welding process to construct the airframe and used thicker walled tubing to compensate. Postaccident examination of the wreckage showed the weld quality was generally poor, and a set of structural bracing components in the main wing spar carry-through section was omitted. Even with the poor build quality, the steel airframe structure appeared to be intact before impact. The omission of the braces alone would not have resulted in the failure of the wing as observed: however, the combined effect of the omission and modifications would have affected the overall structural integrity of the airplane.
From later in the report's Airframe Structure:
The tube widths of all the steel airframe members met the diameters specified in the plans; however, most tube walls were about 30% thicker. The steel tube members appeared to have been welded using the metal inert gas (MIG) arc welding process, contrary to both the kit manufacturer’s recommendations and FAA best practices. According to friends of the pilot, he had elected to use thicker gauge tube because he was using a MIG welder and was aware of the increased weight penalty that using the thicker tube would incur.
The weld quality was generally poor throughout, with multiple areas of incomplete fusion, porosity, and burn-through. Of note, the left fore-aft lower wing box longeron exhibited an incomplete weld to the left aft vertical support, with no penetration, and had detached (figure 3). However, the remaining airframe welds in all other locations were correctly oriented, and appeared intact, with any separation failures occurring in overload just beyond the weld fillets.
The airplane’s plans called for diagonal bracing of the main wing spar carry-through area in the upper cabin. Examination of the airframe revealed that the carry-through structure bracing was missing. Review of the pilot’s build logs and airframe remnants indicated that the bracing had never been installed; nothing in the build logs indicated this omission was intentional.
The designer of the airplane performed a structural analysis to calculate how the omission of the bracing would affect the airframe integrity. The results indicated that the carry-through would lose about 20% of its compressive strength, with little change to tensile strength.
And finally:
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
An excessive pitch control input for undetermined reasons while the airplane was operating above maneuvering speed, which led to a structural failure of the right wing during cruise flight. Contributing to the accident was the poor construction quality of the airplane and the inadvertent omission by the pilot/builder of a series of structural airframe components.
The report, WPR22FA169, is available here: https://data.ntsb.gov/carol-main-public/keyword-search
So, the fuselage was overweight from substituting thicker tubing, many welds were real crap, important parts were omitted, one joint failed completely, but it still took the pilot going well beyond g limits to fold up a wing (not a welded assembly) and make it crash.The National Transportation Safety Board determines the probable cause(s) of this accident to be:
An excessive pitch control input for undetermined reasons while the airplane was operating above maneuvering speed, which led to a structural failure of the right wing during cruise flight. Contributing to the accident was the poor construction quality of the airplane and the inadvertent omission by the pilot/builder of a series of structural airframe components.
The report, WPR22FA169, is available here: https://data.ntsb.gov/carol-main-public/keyword-search
Most any torch can mix acetylene and oxigen and cause it to burn just off the tip. Issues are weight & balance, ease of balancing the flame, variety of tips available, etc. If a torch is hard to use, the welder will tire more easily, which both interferes with learning and interferes with getting work done. I have a Meco Midget (Tin Man Tech sells them) and it is tiny and can get into all sorts of places to weld clusters. Small can work...I have a question about O/A welding equipment. I have a Victor torch set with an oxygen and acetylene bottles. I have always used it for cutting only. I have a Lincoln 225 for my welding needs. The first question, is there an appropriate size handle for welding. My handle with a welding tip seems very large and somewhat heavy. I have seen the small torches HVAC and plumbers use to solder and that looks like a nice size to get into tight spaces. Will it work? I assume changing to my larger bottles for welding convenience.
Look up adiabatic flame temperature for O2-Acetylene and O2-Propane. Then look up melting point of 4130 steel. The bigger the difference in temperature between them, the easier it is to get heat in a particular place, make a puddle, add rod to the puddle, etc.Second question, is can I substitute propane for acetylene when welding? When I got my torch set, I was just a poor new college graduate with a new wife and a child. I could not afford both an oxygen and acetylene bottle so used propane to cut. It was a little slower but worked. Would it impact welding?
Great classes. The point is to spend a long weekend running a torch, puddling, laying beads, and then putting stuff together. If you are capable of learning this, you will be well on your way, and ought to be fine for practice by yourself.Last question, someone suggested one of the Sport Air Workshops to get started. Will it provide enough hands on to feel confident to practice at home and be successful.
Yeah, we teach quiet welding. I had not heard that it erodes the tip, just that it soots up the inside.You get admonished at Oshkosh if you make the torch pop because it erodes the tip. I would say in an emergency fuel off first. Non emergency, however you want.
As long as they pass hydro test every ten years, they are good to go. Really, swap bottles when yours go empty. Let the welding store handle the hydro testing, which they have done for a better price than we can get.In 1988 I bought a few tools at a yard sale and asked the old guy if he had any more stuff he wanted to get rid of ? He said yeah he had his dad‘s tourch, but he thought it was pretty old and
he told me that he’s pretty sure the bottles hadn’t been filled since before the war.
I was thinking the Vietnam war, since it was my war . Now I thought that was pretty old so I set them bottles in the back of the shop and didn’t think anymore about it till one day I came out and my son was using them. I was amazed that both the oxygen and the acetylene worked , Then when I took them in to get refilled, I asked the guy if he could tell when they were last filled.
He looked at them and kind of quizzically asked me if there was any chance that they were last filled in 1928 !
Guess I was thinking the wrong war !
Lol I’m pretty sure these haven’t been tested for about 100 years. And I hope they stay in the family for another 100 so so they along with the rest of the tools in the set have a place of their own in the shop.As long as they pass hydro test every ten years, they are good to go. Really, swap bottles when yours go empty. Let the welding store handle the hydro testing, which they have done for a better price than we can get.
Are you just going to let them sit? Welding supply houses won’t fill them if the hydro test has expired.Lol I’m pretty sure these haven’t been tested for about 100 years. And I hope they stay in the family for another 100 so so they along with the rest of the tools in the set have a place of their own in the shop.
Sadly the hoses broke and crumbled on the way home after I bought the set .
Like I said they haven’t been filled or tested in about 100 years so I suppose they have earned a rest .Are you just going to let them sit? Welding supply houses won’t fill them if the hydro test has expired.
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