tig chrome molly

brian55290 · Sat May 24, 2014 6:49 pm

new at tig welding. I have a ex 250 and the tungsten just balls up no matter what setting I put it on. im new to tig welding but if I turn the heat up it will just melt the tungsten. not sure what im doing wrong. any help would be appreciated.
thanks

Oscar · Sat May 24, 2014 10:12 pm

First check your polarity. Tig torch has to be on the Neg terminal, ground clamp on the positive one. Next make sure you are on DC, not AC. Wrong polarity or on AC will cause balling of the tungsten. If you tell us the settings on your machine it would make diagnosing things easier for everyone.

Superiorwelding · Sat May 24, 2014 10:26 pm

brian55290 wrote:new at tig welding. I have a ex 250 and the tungsten just balls up no matter what setting I put it on. im new to tig welding but if I turn the heat up it will just melt the tungsten. not sure what im doing wrong. any help would be appreciated.
thanks

Another cause could be the type of tungsten you are using. What type do you have in the torch?
-Jonathan

brian55290 · Sun May 25, 2014 6:56 am

Superiorwelding wrote:
brian55290 wrote:new at tig welding. I have a ex 250 and the tungsten just balls up no matter what setting I put it on. im new to tig welding but if I turn the heat up it will just melt the tungsten. not sure what im doing wrong. any help would be appreciated.
thanks
Another cause could be the type of tungsten you are using. What type do you have in the torch?
-Jonathan

I'm using 2% tungsten.
Thanks

brian55290 · Sun May 25, 2014 7:06 am

Oscar wrote:First check your polarity. Tig torch has to be on the Neg terminal, ground clamp on the positive one. Next make sure you are on DC, not AC. Wrong polarity or on AC will cause balling of the tungsten. If you tell us the settings on your machine it would make diagnosing things easier for everyone.

I have the torch on the pos and the ground on neg. ill switch them and see how I do.
Thanks for your help.

RichardH · Sun May 25, 2014 5:03 pm

brian55290 wrote:I have the torch on the pos and the ground on neg. ill switch them and see how I do.

There you go. The heat flows toward the positive, so the tungsten was being heated far more than your metal.
This is also the reason higher power is needed to weld aluminum (which requires AC).

GreinTime · Thu May 29, 2014 7:58 pm

I wish I would have seen this earlier or I could have steered you in that direction up front! As Oscar wrote, the torch and the ground have to be hooked up correctly. The SyncroWave's and the PrecisionTig welders have a switch/dial that you turn
to switch polarity rather than switch leads over. The inverter welders, due to their size and packaging constraints do away
with the switch by having the user change polarity manually. You'll be happy with your PowerTig250ex once you try it again!
Chromoly is one of my favorites to weld (mainly: because racecar) next to aluminum.

Have fun, and happy welding!

Oscar · Fri May 30, 2014 9:39 am

GreinTime wrote: (mainly: because racecar)

I have a bunch of chromoly scraps I need to practice on. All tubing of course. Because racecar.

Does anybody here purge chromoly tubing when tig'ing it? I know one guy who did but he has no pictures and has since let go of the parts he made. I'd like to see the difference in the backside of the weld to see if the integrity of bead can be improved somehow.

Braehill · Fri May 30, 2014 9:57 am

Oscar,
Purging any type of tubing will help the weld. Anytime you can keep the atmosphere off the molten metal the better the weld will be. Almost all the gases in the air in their natural quantities are detrimental not to mention impurities in the base metal that gas off at welding temps.

Len

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zank · Fri May 30, 2014 10:27 am

I backpurge all of my steel tubing. Helps me sleep better at night.