Welding Tips and Tricks

Been many years since I welded, getting back into the car hobby after many years of not having the time or extra money. Back then (late '80s to late '90s) I was never a "good" welder, I was an amateur that made ugly welds that did the job. I really didn't feel the need to hone my skills, was more focused on the other aspects of the car hobby and saw welding as just another tool in the garage. Now many years later, I find it fascinating and want to focus on becoming a much better welder and fabricator.

I bought two machines, a Millermatic 141 for sheetmetal and small jobs, and a Diversion 180 for roll cage and header stuff. In hindsight I feel I should have stepped up on both of them for more flexibility, but it's done - I'll upgrade sometime in the near future and keep the small machines around for track use/backup.

So the job I'm working on now is narrowing a rear axle housing for a friend (funny how all these jobs pop up when someone hears you bought a welder), and it's .250 wall tube mild steel. I realize .250 is beyond the listed capability of the 180, but was told by the sales guy (ex welder he says) that if I multi-pass I'll be fine. So I bought some hot rolled .250 flat stock to practice, beveled the edges as close to 37 deg as I could with a belt sander, cleaned the mill scale, and let 'er rip. I have the Diversion 180 machine set to 180 amps, using 3/32 thoriated tungsten, cup is #7 ceramic, gas is at 20% flow 100% Argon. Filler rod is 3/32 for mild steel.

First set here, the far right was no filler and was cutting in quite a bit. The other two were with filler. To me they look crystallized and brittle? But I don't know.

If any feel like advising on what I'm doing wrong and how to improve, Thanks!



And the back, I don't see signs of penetration?



Second set:

Looks to me like you are not bevelling enough and you are leaving too much of a land. If you bevel more you will be able to back the amps down a bit. Bevel down to a 3/32 or 1/8 land thickness and you can work in the 100-130 amp range and get full penetration.

Louie1961 wrote:Looks to me like you are not bevelling enough and you are leaving too much of a land. If you bevel more you will be able to back the amps down a bit. Bevel down to a 3/32 or 1/8 land thickness and you can work in the 100-130 amp range and get full penetration.

Yeah I wondered if I was doing enough, I'll try another set with more bevel. Thanks!

For tig I use a knife edge on my bevels. No land and no gap. I run about 130 amps and use either 3/32 or 1/8 filler for steel. I do some ammonia pipe that's seamless heavy wall with an overall thickness around 3/8 and I've never had an issue yet. Most of it was pressure tested around 350psi. I often use a miller 150 stl often for its portability.

Poland308 wrote:For tig I use a knife edge on my bevels. No land and no gap. I run about 130 amps and use either 3/32 or 1/8 filler for steel...I often use a miller 150 stl often for its portability.

^^^This. When you bevel for TIG, a land is not needed. And your metal needs to be much cleaner. On both sides.