new 250ex settings

[johnson697]

i purchased a new 250 ex this past summer ...had the older version for 5 years and sold it and wanted to know what settings you recommend for welding aluminum 5052 .100 thick.lanthanated 3/32 tungsten ....keep having problems with either balling up my tungsten or hard arc starting .

[JimMinKent]

i purchased a new 250 ex this past summer ...had the older version for 5 years and sold it and wanted to know what settings you recommend for welding aluminum 5052 .100 thick.lanthanated 3/32 tungsten ....keep having problems with either balling up my tungsten or hard arc starting .

This should get you on a safe path to success:

Torch in Neg
100% Argon at 8 LPM / 15 CFH
About a #6 cup
0.5 seconds Preflow to reduce initial blast
6 seconds Postflow
Balance 25%-30% of Electrode Positive
Frequency 100 hz
No Pulse for now
120 or more Amps AC - throttle down as needed with pedal
2T
Sharpen your tungsten, it will round over slightly upon use
1/4" stickout

For a hard starts:
Make sure the work clamp connection is good
A quick swipe of the tungsten across the work (about 1/2" is all) before you hit the pedal helps
If your machine still uses points, they need to be set to specs

This is a very generic recipe, Have some fun!

[johnson697]

i weld for a living and did alot of aluminum welding with my old 250 ex....the new 1 is just a little different....just having a little problem getting the balance set just right.

[labmaster02]

Why do you swipe the tungsten across the work piece before starting? I heard this before but never heard why.

[Rambozo]

That almost always is because of not enough postflow for the amps being used. You need to have postflow for as long as the tungsten is red hot and just a little bit more. Then you will get nice crisp starts. Look at your tungsten, if it's not bright and shiny, than either not enough post flow, or you got a wee bit too close to the puddle. There is another time that technique is useful. Especially on aluminum, when you want to control exactly where the arc starts, if you make a small scratch in the oxide layer with your tungsten right before you light up, the arc will want to start at that scratch. This is for the same reasons that the scratches on your tungsten can change the way the arc starts. It always wants to come off a point or sharp edge, even if that is a microscopic one.

[JimMinKent]

Why do you swipe the tungsten across the work piece before starting? I heard this before but never heard why.

Here's what Blue has to say on the subject:

http://youtu.be/U2_kWSG0RBg

I don't have to do this very often but it's a good quick fix if you are helmet down and ready, and you get a misfire.

I can appreciate Ram's tip on how to precisely position the arc starting point, too, Thanks Ram!

[Kevin Caron]

I do this too.. It seems like the tungsten gets a little corroded and needs to be cleaned off.

Just a touch of a swipe and you are back in business...

I have also just used a stainless brush to give the tungsten a little swipe and get the same result.

Not sure why it is happening but it seems to work....

[labmaster02]

I'll give it a try.
Thanks