Hello, 1st post, we are making a major effort to upgrade a product prototype to production.

Welding Supplies and questions

Trying to improve the Strength and looks of our welds
Parts have been 4140 tube and 1018 block
Now they are both 4140 Annealed
Have been running 180 AMPs to weld fast and small

Equipment on hand
Miller Synchowave 200 Welder
Negative electrode
Aragon Gas
I have 1/16”, 3/32” and 1/8” collets; 3/8”, 7/16” and ½” gas cups
I have been using the 3/32” 2% Thoriated (EWTh-2) Tungsten with a sharp point
Rod that I have on hand is RG45 1/16” and 1/8”
I use a dedicated 6” grinder for tungsten grinding with an Aluminum Oxide wheel (2) coarse and medium grit

I can pre-heat to 400Ί but I don’t want to heat to 1200Ί afterwards, I don’t want the surface oxidation that results.
I have been burying the welded part in sand to cool slowly as soon as I finish the weld.

Weld needs to be as small as possible but strong


What rod?
What Tungsten?
Amp Range?
What grinding wheel

Thank you
Lowell