about 1985 i visited south pole station they had just lost a whole pipeline of newly installed copper pipe due to the cold almost every joint went crystaline and broke i believe they had preheated before welding but they lost the lot hate to think the cost as all the heavy wall pipe had been flown from the states then had to be flown back.
There better not be any oxygen in that 75/25 mixed gas. Its suppose to be argon/co2 mix. Never experienced it separating either, but I suppose that may be remotely possible. Gene
FWIW to the discussion, I'm using a mig welder with flux cored wire--and I can ***ure you if it's below freezing chances are really good I won't be in the shop. I'll be on here instead
Well to be honest , if it's that cold and you need to weld sheet metal and patch panels , it should be easier to weld . With temps that cold that means the sheet metal will be colder and cool down a hole lot faster . That means faster weldings and less warping ! I will be finding out this same question here in a couple weeks after deer season closes the end of this week . Then it's time to start welding up the rest of the patch panels on my 55 Ford . The really major problem I see with this colder weather is trying to lay some mud down ! I really know that will never work for sure . I do have a wood stove to help keep the cold garage a little easer to withstand . Mine is a pole barn with no insulation and no money to have it done . It still keeps the damn cold wind off me along with the rain and snow . At least I have a chance to work on my hotrods in the winter time that many guys/gals can't do at this time . So cold or not I am grateful I have a roof and 4 sides to help keep the weather off me . Retro Jim
Don't take it personal that I quoted you, I just want to address your point. The heat difference is not 40 degrees, From 30 to 70 Fahrenheit it's 40 to 350 or 400 degrees. Technically a quality tested weld is to be preheated and in some cases temper cooled. On pipeline welding the one danger is warp. If you start to run a bead on the pipe and have a cold side and a hot side and temps all over you will gat a warp and have warp cracks. Preheat equals less thermal shock and warpage. In many cases especially where a line is going into a cold environment it will chill so fast that it can split or crack. Now per the OP, if you want nice stuff and are stacking dimes or welding Aluminum than yes absolutely this will improve your skills, the look the metallurgy all of that, in most cases with what we do it may not have to be that perfect but it absolutely does make a difference. You could see it if you did a scan or test and it would be visible on an electron microscope. So yeah, if you were gonna get certified for your welds, those would be preheated and temper cooled so they could be sweet.
Yes, you can tig weld copper, you can use sheet or tube and use electrical wire of various sizes as filler wire. In the right application it is very cool visually. You can polish out the seams as well.
for my .02 cents worth, i work in an open pit mine, up in the north. i've watched welders repair cracks in 250 ton haul truck frames. at -30 below c. there is a pile of paper the guys have to go thru to make wcb, the goverment and the union happy! the bottom line is a good weld good penitration. the welds may look a little sloppy on the final p*** or so, but that is largely because by then the welder is shaking like a dog pooping razor blades! in short cold weather does not seem to affect this type of welding
Just to insert a little common sense into this...If your garage is warm enough for you to play with your toys, you won't have any problems with any welds. It's one thing to have to work in those conditions to earn a living. It's another thing to go out and play in it. If you can handle the conditions with a heavy winter jacket and gloves, don't fret it. If you are out there in sub zero temps....you might consider counseling.
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