You just need proper fit up and fixture. I have a manual weld cert on 0.016” thick sheet that allows me to manually weld down to 0.011” thick. Maxstar welder, no pulse settings, 1/16 tungsten, 0.020” filler, number 10 shade in a cheap $20 helmet.
Leave a gap in the material in the shape of a V and as you weld the V will close in front of your puddle due to weld shrinkage.
This does require a fixture. A very simple fixture for short (6” ish) welds. However it does take some setup. Longer welds just take more thought and setup.