Hello, when trying to weld aluminium, just before the puddle starts the tungsten burns away up into the cup? tried everything, gas, amps, ac balance, pulsing, background amps, tungsten size, tungsten type different pieces of aluminium . I've tried everything. any help? welding steel or anything else on dc is fine, just the ac is the problem. ? please give me advice. many thanks
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Davek0974
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Wow, exactly the same problem I had a day ago when I tried ally for the first time!
I've got an r-tech tig161 AC/DC and as you had, the electrode just balled up and then melted right back in the cup.
Tried a few other settings but as I'm still learning steel, I gave up on the ally.
Will be following this thread.
I've got an r-tech tig161 AC/DC and as you had, the electrode just balled up and then melted right back in the cup.
Tried a few other settings but as I'm still learning steel, I gave up on the ally.
Will be following this thread.
this is on my friends ac dc tigl one of those cheap things, but I've seen someone else's work before. it has start up amps, current amps, background amps, then down slope.
then below it has , pulse width, ac balance pulse duty and pulse frequency. but even without pulse on its same. i had similar problem with a r-tec swell. never was resolved. i just don't understand how a tungsten can burn away so fast?
then below it has , pulse width, ac balance pulse duty and pulse frequency. but even without pulse on its same. i had similar problem with a r-tec swell. never was resolved. i just don't understand how a tungsten can burn away so fast?
What dia tungsten at what amperage? Post a pic of a used tungsten, is it clean and shiney or discoloured?
Approx 2/3 of the arcs heat occurs at the +ve electrode which is why DC TIG is virtually always DCEN. With AC the tungsten has to endure more heat which is why a blunt/rounded/balled tungsten is traditionally used with AC. The tip WILL melt, and tungsten dia - amperage relationship isn't the same as it is for DCEN. Different tungsten flavours are also traditionally used with AC but that's not gonna make a night or day difference with regards to how much the tip melts. If it's melting right back into the cup something is obviously wrong... if the AC balance is biased too far towards EP (cleaning) it'll melt more, if the polarity is wrong the AC balance will work backwards but then if the polarity is wrong the tungsten would never survive striking an arc in DC
Approx 2/3 of the arcs heat occurs at the +ve electrode which is why DC TIG is virtually always DCEN. With AC the tungsten has to endure more heat which is why a blunt/rounded/balled tungsten is traditionally used with AC. The tip WILL melt, and tungsten dia - amperage relationship isn't the same as it is for DCEN. Different tungsten flavours are also traditionally used with AC but that's not gonna make a night or day difference with regards to how much the tip melts. If it's melting right back into the cup something is obviously wrong... if the AC balance is biased too far towards EP (cleaning) it'll melt more, if the polarity is wrong the AC balance will work backwards but then if the polarity is wrong the tungsten would never survive striking an arc in DC
Tigman
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Hotrodders bang on the money , ac balance too high putting more heat into the tungsten , if your just starting out with tig ac , then forget pulse and all the other bells and whistles just set balance 50% frequency the same and try to weld , if tungsten burns away turn down the balance try again , little post flow and a bit of pre flow wont hurt none
no dave, r tec welder ones stay same and my friends stay in same place. ...... the tungsten is a very shiny blue colour and looks just like its been polished at high heat. ill take a picture tomorrow when i go see him again and ill give it a try and ill show you it with dc. we use grey tungsten and green tungsten 1.6 and we tried a grey 2.4 tungsten then a white 2.4 i think. still no difference, just same
Tigman
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Ac = Alternating Current it switches between polaritys ! turn balance toward negative , heat goes from tungsten to work , work gets hot , turn toward positive heat goes from work to tungsten , tungsten gets hot .
DC = direct current goes one way en work gets hot !
DC = direct current goes one way en work gets hot !
whm_fab
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Don't forget The r-tech user manual is **** ways, on the balance dial on a tig161 anti clockwise is penetration and clockwise is cleaning. Think of it as the cleaning dial, turn it down is less cleaning turn it up is more
Richard.
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There is not a fixed polarity for Ac it bounces between the two. What Hotrodder was saying if the polarity is reversed on ac then adjusting the balance could be in reverse so trying to go towards the dcen for penitration could be dcep by mistake cleaning and balling up the tungsten too much. But the op says it works in DC so that's that theory shot.
