None of this is really aimed at you Kevin WarEagle or anyone's abilities, just some general thoughts to consider about thin metal. I struggle with it all the time. Getting a little better at it.
Cut a bunch of slits (use a .040 or .060 disc) in the old patch panel and weld them up for practice and experimentation. It is hard to get the knack. Change settings and write them all down, try various angles and stick outs. That is the ONLY way to learn thin welding. To learn your machine and what methods work for you. Sometimes hot and quicker works, sometimes slower and not so hot. Sometimes you have to use a long stick out, sometimes a short is better that day. Mix it up during practice. Change duration of the trigger till you develop a method. Weld while you can reach the knobs with one hand while practicing on the slits. Turn the settings while welding to learn/see/hear what happens. Only use stacked dot welds 1-3 seconds. Slide the torch a tiny bit, down the gap, across the gap, whatever seems to work. Sometimes starting on the gap and moving to the last dot works because as the "puddle" gets hotter it then gets to the thicker spot. Other times it's the opposite.
Starting at edge of previous spot works better. There are human factors involved here that can't be specified.
I hope you are using MIG with gas. Everything else is no good for thin. Some use .024, I use .030.
I do use copper and brass backer sometimes.
Mig is pretty easy to learn, but not thin metal. All metal has to be new or like new. You take .041 thick 19 ga and it has pits or wear or thinned by rust, you got .025 thick. NO GOOD. You take .047 18 ga with problems, you got .030 or less. Now factor in that those gauges have a +/- .004 thickness tolerance. This applies to the original USA metal on the truck. The Chinese patch panel tolerance is unknown. Anyway the key is practice and experimentation. An old dented, no good fender or hood makes a great practice piece. Of course you always want to use a practice piece with the same gauge as the task at hand.
You MUST clean the area near the weld down to bare metal without taking away any metal. BOTH sides if possible. MIG DOES NOT TOLERATE contamination. I also try to trim the wire stick out as much I can.
Don't keep welding without clipping a ball end/burned end. You are doing quick spots, you need a super quick start and stop arc. You don't need to trim stick out when plug, stitch, seam or weave welding.
You must also clean a ground spot somewhere for the clamp, down to bare metal. BOTH SIDES for the clamp. If you can only clean one side, place clamp jaw that has the cable on that side.
Once you find the correct machine settings and torch methods, don't expect it to work exactly the same the next time. But it will be fairly close and you will be better at it.
1. Weather can change
2. Extension cords cause voltage drop
3. Output from your electrical outlet can change (utility company's fault)
4. Dirty/worn contact tips
5. Different thickness metal
6. Too much coffee
7. Not enough coffee
As everyone knows you have to have air ready at hand to cool almost each spot dot. Why not? You have all day to weld, all week, all month. if you warp it because you are lazy/in a hurry, you will have your worst nightmare. Possibly unfixable. Remember that.
Lotta stuff here, but once it's a habit, it can create more success.
