Welding Tips and Tricks

I am trying to weld 16 gauge mild steel to 5/8" mild steel square tubing, and can't seem to find the proper settings and/or techniques to make it work. I'm using a Maxstar 200 TIG machine, argon gas (11cfm), 3/32 rod, 1/16 tungsten with cup size 4, and have tried everything in the range of 90 - 120A with only ugly results. I think I should be using thinner rod, but it's all that I have available -- is there any way to make this work? Thanks for any help.

90-120 is a little high for that thin of material. You'll burn right through it. i usually stay around 45-60a when working with 16GA. now obviously its not going to penetrate the 5/8" very much so you'll have to find a happy medium. Just make sure you have both surfaces good and clean before starting.

Really need smaller filler rod too, will make it easier for to get a better looking weld. That 3/32 gonna freeze the puddle quick.

You need to concentrate the heat on the thick metal and kinda wash the puddle onto the thinner metal. Welding thick to thin is a challenge. Some pics of what your welding would help. 120 amps won't make a dent in 5/8" steel. You need enough amps to start a puddle in the thick metal . Try using some MIG wire for filler if you have any.

What is the wall thickness of the 5/8" square tubing?

i forgot to mention i was using 1/16" 70S6 filler.

Thanks, everyone; I'm going to take your advice off to my shop now.