Welding SS material.

You can weld with electrodes as well on DC or AC, but DC runs smoother. It leaves a hard residue, that with cooling down jumps from the SS weld onto you. Although on 316L I prefer MIG and TIG welding under inert gas protection. Also DC source. (If the polarity is wrong you will immediately see the difference... with Tig you will need to run to grind down your needle) The gas needs to flow so that you have your area protected. It depends on how the airflow is inside, that carries away the gas. With TIG you will see that your arc will be diverted - than you have too much gas. Outside with gas is only possible when no wind. If gas is not enough you will encounter small volcano- like craters (starts microscopic) so this means you need more gas and clean out the bad welds. Use a grinding or cutting disk that you preserve only for SS, the same for all tools, even your steel SS brush - where you touch with Fe contaminated tools your SS will rust. More than a manometer to check your pressure, I prefer a floating ball flow meter. Since your gas cost also this needs to be calculated in the cost. I use a mix of Argon and CO2 - about 90/10 volume percents. Current settings depend also on the mass of your material and the width and depth of your pass. Heavy pieces need a gap. Thin stuff can be put almost together. SS steel plate tends to bend and wobble when too much current is applied. Weld in parts, and fill these in afterwards. Plate of 6mm and thicker we try to weld from both side simultaneously. (2 welders) We bring down the tank pressure to about 1- 3 bar (42 psi) depending on the length of the feeding hose. Small welds require no more than 0,4 (normal) liter min if welded with a short arc and low amperage (like 40-50 amps) - small wire and thin material. I listen to the flow, more than looking onto the meters. Most important is that you SEE your molten path and material. Sometimes you'll need a shade screen #9 or even 8. The travel speed depends on the feed - the gap you want to fill needs to be full and comes out of your electrode or wire(s). If you compare the volumes, you know what you need. The speed is space you fill up to the time to melt your materials together. I should first make some test on horizontal welding on scrap material. Check and change for improvements.