There is a simple rule of thumb for tig welding aluminum that is not very accurate but can help as a starting point.
That is one amp per one thousandths of thickness.
This simple rule is more accurate for carbon steel than aluminum because aluminum often needs more amperage.
But for an .030" 1g butt joint 30 amps can be just right
WELD PROCESS = TIG, GTAW, GAS TUNGSTEN ARC WELDING
METAL TYPE = ALUMINUM 6061
THICKNESS = .030"
WELD TYPE = GROOVE WELD
JOINT TYPE = BUTT
POSITION = 1G
AMPERAGE = 30 AMPS CONTROLLED WITH FOOT PEDAL
TUNGSTEN = 2% LANTHANATED, 3/32"
FILLER WIRE = 1/16” 4043
POLARITY = AC
GAS FLOW = 15 CFH argon
CUP SIZE = 6
ADDITIONAL SETTINGS = AC BALANCE 33% CLEANING, AC FREQ 150HZ
PRE FLOW = 1 SEC
POST FLOW = 10 SEC
TIPS: KEEP A FAIRLY TIGHT ARC AND WATCH TORCH ANGLE
Aim for an arc length that is equal or less than the diameter of your tungsten electrode.Torch angle can be forgiving provided your arc length is tight.