Tig Welding Steel – 309 Filler Rod

309 Filler Rod

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Tig welding carbon steel is often done using er70s-2 tig rod… and for good reason. It works. It’s cheap. And it’s predictable.

But there are times when using 309L tig welding rod works great.

309 stainless tig rod is more expensive than er70s-2. Like around 4-5 times as expensive.

Where I live, you can get er70 tig rod for less than 3 bucks a pound. 309 stainless costs more than 10 bucks a pound.

Now, some random thoughts on using 309 rod for carbon steel jobs.

I don’t think its a good idea to use 309 rod for everything because under certain conditions it might be prone to hot cracking…like on full penetration groove welds, and highly restrained welds too.

309 tig rod is designed to be used to dissimilar welds of carbon steel to stainless.

309 works for all kinds of odd jobs…like tool and die repair where high hardness is not required, tig welding 4130 chromoly to stainless, welding over hot rolled mill scale, sealing a hole when water is present, and more.

Using 309 indiscriminately where er70s-2 works just fine is not only more expensive, but is not as predictable.

But honestly, just being real, I would be hard pressed to describe an odd job on carbon steel, where it would not work.

( And as always, feel free to visit us at our sister site, WeldingTipsAndTricks.com. )

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  1. Hey Jody,
    I really appreciate all you tips videos, sure helps to see a hands-on approach to everyday issues that crop up. The books out there only cover so much, it’s field experience that really counts. That tip on using 309 to boil out contaminates is great, I’ve tried it recently on some thin carbon steel that was giving me fits with ER70 rod and the stainless worked flawlessly.
    Thanks again,

  2. jody. iam new to tig welding and have enjoyed your viedos. I have learned alot. i have a question about cup size. when tigging stringer in a grove does the cup need to be smaller to fit in the grove or large cup like an 8. and when tigging a cover what is recomend for walking a cup on pipe for the cover pass? and why do my cup chipp what am i doing wrong. ?

  3. Hey there Randy, try clicking on the Video of the week tab on the top and go from there works for me every time.

    Regards Vinnie (Australia)

  4. have been getting welding tips vidios for 3 weeks now, however there isn’t any ‘start/stop’
    controls below the vidio so i can’t run it.

    is it on my end or your end?



    • Randy,

      Thanks for the feedback. To be honest, it’s hard to know who’s end is causing the problem. If you browser is all up to date, including plugins like Flash Player and such, you should be all set. Sometimes, people browsing with Internet Explorer have real problems. It’s an inferior, rarely-updated browser. I recommend downloading Mozilla Firefox or Apple’s Safari. Both are free, and both are great.

      Let me know if this helps. Regards, Jody

      • Hey Jody,
        I too am having problems with the vidoes for the past two weeks. I downloaded Firefox like you suggested to another person and the videos still won’t play. Do you know of any other troubleshooters. Thank you.

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