This video shows tips for passing a 3g tig welding certification test.
A 3g plate test using tig is not all that common but it is done sometimes.
One main issue with this test is whether to walk the cup or not.
Lets go over some tips...
First things first.
**Clean the metal at least 1/4" back from the edges of where the weld will be.
**Using a 1/8" tig rod, gap the 3/8" plates and tack weld on the ends.
**The goal is for the gap to be just tight enough to where a 1/8" rod wont fit.
**At about 100-110 amps , using a tight arc length, lay the rod in the groove and move the electrode forward and backward in a 2 step forward 1 step back type motion.
**Pay special attention to the technique used for stops and starts. I didnt use a grinder .
**For the hot pass, I only increased the amperage by 10 and each subsequent pass, I increased amperage by about 10 until I topped out at around 175.
**I used a 3/32" 2% lanthanated tungsten electrode and a # 6 cup for the root pass but a 7 or 8 cup would have worked better after the root.
The techniques used for this 3g tig welding test will work for pipe. I didnt have pipe coupons on hand for this video so I used plate. But amperage, techniques, etc. work the same for tig welding pipe.