Oxy Acetelene welding strenght ?

admin

Hello,Im not by anyway a qualified welder, Although have completed a course on TIG and have some oxy acetelne welding equipment at my dispoal for general use. Before I ask this question Im aware that there are probably thousands of variables and the main one being who is holding torch ! (lol) but metal properties / gas pressures filler rod types and all other things which get dragged up. For argumets sake.....If a welder, welded a piece of 2mm of mild steel together with the pieces butted together end to end. How strong would you expect it to be ?Should you be able to bend it 90 degrees, 90 degrees and back 90 degrees the metal to break before the weld ? I hope you can understand what im getting at, Im not trying to open up a whole debate Im just curious. Im sure there are better methods to weld things perhaps MIG TIG whateverCheers Geoff thoughs and experinces welcome
Reply:Oxy/acetylene welding was the basic welding discipline until the 1940s. During the '40s engine driven gasoline welders became acceptable on the pipelines and plant jobs. An OA weld, done correctly, will test with the acceptable methods accorded SMAW, GMAC,.GTAW AND FCAW.Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.                                         -Cree Indian ProverbSA 200 LincolnVictor Torches
Reply:Oxy-acetylene was also used to weld tubular aircraft frames, and race car frames.  Its plenty capable, and in the right hands can give a result similar to TIG (given the right conditions).In mild steel, a weld should be the strongest part of the metal, with the heat affected zone (on either side of the weld) probably being the weakest.  The parameters of your question are pretty vague however.
Reply:Back in the day, I qualified with oxyacetylene on a 1/4' wall tube in the Arkansas bell hole to section IX, ASME B&PV Code using RG65 filler.
Reply:I welded 35 yrs, using stick 99% of the time. I qualified 20 yrs ago on Mig & Tig as it was called then, but never really used them. I can cut very well using O/A but have never used it to weld with, the few times I attempted it were abysmal at  best. I've heard many references to the "Arkansas bell hole" over the yrs but have never taken it, we used the 6G (before it was called 6G) to test with and called the Arkansas bell hole?Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.                                         -Cree Indian ProverbSA 200 LincolnVictor Torches
Reply:Hello Geoff, as you said there are many different variables and parameters that could play into an answer to your question. In general terms the strength of Oxy-acet fillers when compared to GTAW fillers are not quite the same, generally GTAW fillers are higher in tensile strength. Yet, that can be misleading because the tensile strength of most mild steel parent metals is below these tensile strengths so it's basically a wash when trying to make that sort of a comparison. Weld puddle characteristics is another thing however, Oxy-acet welds will generally exhibit a relatively shallow penetration characteristic when compared to bead width, GTAW will generally exhibit a much greater penetration to bead width characteristic which can be further influenced by the tungsten grind angle. Long taper, shallower penetration, steep grind angle on the end of the tungsten, narrower and deeper penetration characteristics. If you are trying to determine whether you can perform a butt weld with the Oxy-acet process that could withstand bending, straightening, and re-bending, I say it is possible, but only if a number of specifics are met while the welding is being done. This might include proper joint set-up and preparation, correct tip size, regulator settings, flame adjustment, rod type and size, correct application of operator skills, and finally, correct post weld handling of the welded joint. Even though mild steel is generally unaffected by a water quench in theory, I wouldn't suggest it if I were planning on subjecting the weld to the bending you have suggested. I'll throw one additional bit into the mix here, if I were to set up two different butt welds identically with the edges up tight to one another, it is much more likely that I could possibly achieve complete joint fusion with a GTAW process than an Oxy-acet one, mainly due to the characteristics of the process and not that one or the other can make a more sound weld. I hope this makes some sense and is somewhat you were looking for in the way of an answer. A bit for your consideration, best regards, Allanaevald
Reply:Hi guys,Yeah some good thoughts there, Thanks for your responsesGeoff