Out of my element...

[Chainsaw]

...and no one else in the company can assist me.

Since October, I have been designated as the test guinea pig - whipping boy, for our company to become certified/qualified in 2G and 3G for the latest ISO's out there for Gov't contracts using GMAW.
I've been welding for 25+ years and this go 'round I've tested on all sorts of steel alloys from 8" coupons to 30" coupons that get x-rayed then, they go through the tensile tests.

With all of that complete, this week I begin the aluminum portions - something I've never welded out of position - and I am required to use 3/64" ER5356 aluminum wire on 1/4" plate, set up for 3G with a 1/4" open root with a 1/4" backing plate of aluminum.

The testing labs tell me that I cannot use my usual weaving pass as on steel, and have to drag it straight up at a minimum of 180 amps and 25 volts - maximum of 225 amps and 27 volts.

The machine I am using has a wire speed control inside the feeder, outside of the feeder on the front, and on the gun itself that contols the previous two contols.

I was able to get the parameters required, but I'll be danged if I can get the first two roots to look like something that you'd want to call a root.

Does anyone in these forums know anything about the technique I should be using, as these 1/4" coupons have to pass x-ray and tensile?

[bwldng]

You might try the local career training school welding instructor.Another help might be the pipefitters union in your area.Or the company that built the welder you are using.Good luck.