New guy TIG questions

[James2]

Hi everyone, new guy here -

Great questions and answers. Well, I should be receiving my first TIG machine tomorrow, an excellent condition Maxstar 140. I'm welding 4130 tubing (1" diameter, 0.058" wall) into a roll cage with 1.625" 0.083 tubing. I have a few simple questions in preparation:

1. I bought some ER80S-D2 filler rod. I had a hard time finding it since most supply houses around here said they don't get many requests for it. How do I know the welding shop gave me the right stuff? There doesn't appear to be an identification stamped into the rod.

2. What baseline settings would you recommend? (Amperage, etc.)

3. The machine came without a torch/regulator/flowmeter. A local welding shop has a brand new 150 amp air-cooled torch that was taken off a Maxstar 150. Will this fit the Maxstar 140? Anyone have some torch/regulator/flowmeter recommendations?

4. I know that tight fit-up is key. How much gap is too much to fill-in?

Thanks for any help. I appreciate your advice.

Thanks,
James

[Rob]

James2,

Welcome! Sounds like you're doing the NHRA helmet-bar update on a drag chassis. As for baseline setting, try 45-50 amps, with a flow of about 25-30 cfh argon, and 1/16 rod. This has worked well for me on various diameters of .058 wall CM tubing. May need to add a bit of current for the .083 and favor the thick tubing side of the weld.

As for fit up, make it tight. Use a notcher or even a hole saw chucked in a drill press, but you want the tightest fit you can get.

Your ER80S-2 is a good choice. It would take some serious testing to definitively identify the filler, but if it has no stamp near either end you just have to trust your supplier. If your supplier is reputable, they're likely what he sold them as.

As for torches, I prefer a small air cooled torch so it's easier to work your way around tubing. If it's a quality torch and has the contactor/current control set up you prefer, it should work well.

Let us know how your project turns out.

Rob

[James2]

Thanks for the tips! Used a tubing notcher to try to keep the gaps to a minimum, but it was kinda difficult with the compound angles. Hope it isn't too big. Will see how it goes!

Thanks again,
James