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hi,my hobby welding has so far been limited to mig on mild steel. out of curiosity i've been reading up a bit on welding aluminum. now, what puzzles me is that that dc tig welders are supposedly almost impossible to use for aluminum due to the lack of cleaning cycle, but in the same time mig welders are commonly used for aluminum welding. since mig welding is dc welding and subsequently lacks cleaning cycle, how can this work?
Reply:It's not AC that provides the cathodic cleaning but the EP (electrode positive) phase with AC TIG. Around 2/3 of the arcs total heat is at the +ve electrodeMIG wire is 'disposable' i.e. you want it to melt in order to weld so DCEP is used. TIG tungsten is not disposable, need it to maintain the arc. The extra heat with DCEP means that massive tungstens are needed even at low amps (a 3/32" is good for only around 30A DCEP). so not too practical. DCEN means no cathodic cleaning, can be done but again not too practical for the majority of applications, particually manual welding. AC is the solution, enough cleaning action to break up the oxide layer and while the tungsten has a harder time it can cope because it's only exposed to EP for brief periods
Reply:so a mig welder is constantly in a (dc) cleaning phase but the same is not practical with the a non-disposable tungsten tip. makes perfect sense - thanks for straightening it out for me!
Reply:what he said . "hotrodder"and to use DC ( mostly thick AL. ) you need helium gasidealarc 250/250 ac-dc tigidealarc 250/250 ac-dc tig #2 used for sticklincoln sp100hh125dual arbor grinder polisher30 yrs of hand tools52 pitch blocks 6p-26prake gauge -pitch gaugeG&D prop repair 918-207-6938Hulbert,okla 74441
Reply:Originally Posted by d94joncaso a mig welder is constantly in a (dc) cleaning phase but the same is not practical with the a non-disposable tungsten tip. makes perfect sense - thanks for straightening it out for me!
Reply:Originally Posted by d94joncaso a mig welder is constantly in a (dc) cleaning phase but the same is not practical with the a non-disposable tungsten tip. makes perfect sense - thanks for straightening it out for me!
Reply:Electricity flows from neg. to pos. despite popular belief. Where it goes determines where the heat ends up, with TIG, DCEN is the preferred route because it takes the heat away from the tungsten (electrode neg.). The reason AC is used to weld alum. is for the alternation between the two polarities. The electrode neg. melts the base & filler metal while the electrode pos. "pulls" contaminants from the weld pool."SOUTHPAW" A wise person learns from another persons mistakes;A smart person learns from their own mistakes;But, a stupid person.............never learns.
Reply:Originally Posted by Rojodiablo You generally need helium, and retarded clean aluminum to do it, as there is literally NO cleaning action.
Reply:It's the same as stupid heavy bricks or crazy clean socks.Lincoln PowerMig 180cVictor O/ABandaids and aspirinI don't know what I don't know!?
Reply:Tom,That would be really-really-really-really-really-really-really clean aluminum. So clean that you :- feel like a retard when the boss tells you to keep cleaning a piece of aluminum that already looks clean;- feel like a retard or at least a space cadet from all the volatile solvent fumes wafting up as you keep scrubbing that nice shiny piece of aluminum with a clean and never-used-for-anything-else-except-this-task stainless steel wire brush and some volatile solvent like acetone. The best laid schemes ... Gang oft agley ...
Reply:Originally Posted by MoonRiseSo clean that you :- feel like a retard when the boss tells you to keep cleaning a piece of aluminum that already looks clean;
Reply:Ha! I thought he was serious.DAG NABIT, I left my tape on the saw.Wild Fire Welding
Reply:He was. |
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发表于 2021-8-31 23:41:50