welding alum with poweritig250

[mrmuddy76]

i recently got a poweritig 250 and after some confusion with tungstens and shielding gas . i Finlay got the write set up and can weld steel like a pro( more or less) and i had some scrap aluminum laying around so i took a stainless wire brush and cleaned tell it was spotless and struck an arc and all i got was a blob. no matter what i tried and couldn't get any thing but a blob.
i tried adding some filler rod and it also melted into the blob?

so does any one have any suggestions ???

[performance]

I assume you are using AC>

Turn balance down to about 35% and turn frequency up to about 120

What does your tungsten tell you?

It also sounds like you are getting oxidation, possibly not getting metal clean enough.

[mrmuddy76]

no on the poweritig its on dc with pulse controles...so no high freq ac. but i have heard people say tat have welder aluminum on dc?

[performance]

Muddy,

Again, it would be a good idea to read the manual. There are safety warnings, hints, and technical tips that you can use to save your life and a lot of time. Please read it for nothing more than the safety warnings!!!

Where ever you are getting your information from is not giving you sound advice.

While technically you can weld on DCEP aluminum, you will make a fine mess doing it with straight argon. Helium or an Helium/Argon mix is used for DCEP welding of aluminum. I surmise also that you are using DCEN. Is your torch in the negative lug? If so this is DCEN and is on the wrong side. This will make the biggest blob you have seen because, despite your best cleaning efforts, a layer of oxide still exists and the aluminum under it melts before the oxide layer and by the time you burn through the oxide, you have made a molten mess of things. You will not have the experience or the patience to use DCEP either as it will eat up tungstens if you are inexperienced and only provides shallow penetration. The DCEP provides the cleaning necessary, but heats up the tungsten quite quickly and will easily form too large of a ball.

AC is specifically designed for aluminum. AC high Frequency welding was developed because so many people had "blob" problems. The AC assists in cleaning the oxide off the metal. The pulse will help control the heat input and make it easier to weld with while in AC.

We do not sell our I-Tig welders to weld aluminum ( I missed that it was an I-Tig unit in the original post). Some people want to know if it will weld aluminum. We say "yes" because they will in the right hands. But if they have to ask that question before they buy, then they probably don't know enough about it to try when they get the unit.

[JJW]

mrmuddy76,
A DC only machine can weld aluminum, but...

Stick Welding: DC electrode negative, with flux coated stick welding rod for thicker aluminum above 3/16".

TIG: DC electrode Positive, you can do very thin aluminum if you use a very large diameter tungsten, most all the heat will be directed at the electrode, the aluminum will be a frosted etched surface because of the pure cleaning action.

I've seen other people DC TIG on aluminum. I've tried it, it's nothing I would recommend.

Good Luck,
John

[JJW]

HEY!

Look back a couple of threads.

stick welding aluminum with my Super250P
by: hildstrom

[performance]

JJW,

The Tig torch electrode should be Positive, not negative to weld aluminum in DC. This allows the electricity to flow from the workpiece to the electrode. This is what breaks up the oxidation. Electron flow from torch to Workpiece will not allow this to happen.