What's Wrong With My TIG Tungsten?
A viewer visiting from Florida, Georg, has a question about his TIG tungsten. Why does it get crusty, rusty and ugly looking?
Kevin asks if he is dipping the tungsten into the puddle. No. Is he hitting it with the filler rod? No. Then, Kevin says, he has a different problem, especially down in Florida where welders have to be especially worried about rust and contamination.
A little test should show exactly what the problem is! Kevin has 3 pieces of 1/8" mild steel plate. One is bright and shiny metal that he cleaned up with the grinder and wiped down with acetone. One has a little bit of surface rust on it. The third piece is just full-on rusted.
Kevin has 3 clean, sharp tungstens. He's going to use one to weld on the shiny metal, the second he'll use to TIG weld on the steel with a little rust, and he'll use the third tungsten on the totally rusty metal. Then he'll compare the 3 tungstens. That should show exactly what Georg's problem is.
Kevin is using Everlast's PowerMTS 221STi, which is a multiprocess welder - it can MIG weld, TIG weld and stick weld (arc weld). He has it set in TIG welder mode at 136 amps available to the foot pedal
Kevin and Georg put on their welding helmets and other safety equipment. Kevin TIG welds on the clean metal, changes his tungsten and welds on the slightly rusty metal, then changes his tungsten again and welds on the rusty metal. You can see the sparks flying off the rusty metal as he welds.
Then he shows the 3 tungstens. The first one still looks clean and sharp. The second tungsten is clearly more rounded and used looking, and the third tungsten is really nasty. That points toward contamination of some kind.
Georg asks where the contamination comes from, if it is just that the dirty metal jumps to the tungsten.
Kevin says yes. He explains that TIG welders are reverse polarity. That means that the workbench and ground clamp are positive while the TIG torch is negative. So the contamination is pulled from the metal onto that red hot tungsten during welding.
That confirms that cleaning the metal is everything, especially in a place like Florida where it rains and the humidity is high, but even in Arizona. Yes, cleaning the metal for TIG welding is critical. You want to grind it clean, then wipe it with some acetone or something to clean it.
Kevin hopes that answers Georg's question as well as that of any other viewers who wondered how their TIG tungstens get dirty.
Kevin is ready to go back to work, but you might want to stick around for another moment to see Georg get indoctrinated into the vagaries of shooting video ....
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