Jeff, what helped me as much as anything is creating controlled test. Simple well know stuff that had no variables. Metal - Gauge - Tungsten - Filler - Gas Flow - Amperage. Fit up, prep, and clean meticulously so there's no doubt.

Then I use the baseline's Miller provides as reference.

Run a 1" bead at your baseline, then one inch beads at high and low extremes to the baseline and observe my habits during the tests and the results. Knowing the extremes has helped me understand right vs wrong and get the feel for normal or an acceptable average.

Any recommendations on tungsten and filler size for sheet metal, 20 gauge specifically?

1/16" and 1/16" should work.

Miller app only goes down to 1/16" material

For butt joints they say 50-80 amps for stainless +10% for mild steel.

Argon at 11 cfh or 20 psi.

Speed 12" per minute.

Prep and fit-up!!!

Download the miller welder app --- it has all that info at your fingertips.

Watch this on tight fit ups!!!










and watch this video too…..

I actually got rid of my smart phone and went back to a "dumb" phone! I use the Miller calculator on their website, but, like Sieg said, it only goes down to 1/16 so I wasn't sure. I had watched that first video before, I watched a ton of Jody's videos when I first bought the TIG. That's where I learned of the online tubing coper, awesome "tool".

I'll give it some more practice when I get a chance to work on my own pickup again. Until then I'll stick to the larger steel or a MIG.

In general the filler should match the material thickness, so for 20 Ga I would use .045 , or even .035 if you have a tight fit that doesn't require much filler.

Created a project to get some heavy gauge practice on. The heavy stuff was good for me and my aging eyes as it's like looking at the puddle under a microscope. :D

Basically I welded a piece of seamless tube with a 12mm wall and 34mm ID to a 13.5MM base plate. The tube was beveled at 45* giving it an approx. 7mm face.

Tube fuse tacked to base.
http://photos.smugmug.com/photos/i-M...MRJ9WHs-XL.jpg

I alternated fusing opposed 20mm sections.
http://photos.smugmug.com/photos/i-C...CjWGc4d-XL.jpg

Fused 360*
http://photos.smugmug.com/photos/i-p...p9kCCdp-XL.jpg

Then I started experimenting laying cover passed by dabbing 1/16 70S rod and 3/32 70S, then lay-wire method with 3/32. I lost control of the heat due to puddle chasing mainly related to poor positioning/posture techniques.
http://photos.smugmug.com/photos/i-f...fhNjDdq-XL.jpg

Final pass using 3/32 lay-wire and weave pattern with the torch.
http://photos.smugmug.com/photos/i-h...hZ4RGW3-XL.jpg

End result
http://photos.smugmug.com/photos/i-H...HJ2K99q-XL.jpg

I plan on stress testing it in the near future.

The larger material was good practice for me as most of my practice has been at a much smaller scale. The visual scale made connecting the dots much easier. A water-cooled torch would have been nice to protect from the material heat, surprisingly the torch never got uncomfortable with my non-insulated TIG gloves. A TIG Finger for heat protection would have been nice when propping on the tube though. Ended up laying my insulated MIG glove over it. :thumbsup:

So first things first --- it looks real good -- and projects like this teach a guy A LOT --- such as you mentioned -- positioning and clamping and heat and on and on…



#2 -- when we say CLEAN is the paramount thing to TIG welding (MIG you can get away with a lot) ---- I would have cleaned the mill scale off down to clean bare shiny metal…


Did I mention it looks real good?

Thank you!

It was clean metal in the weld circle. Didn't have any contamination flares at all which really surprised me.........other than sticking the tungsten in the puddle 3 times.....which is a win for me. :D