Still learning my way around the new TIG machine - Wire choices

[Bob La Londe]

TIG WIRE ER70s6 vs ER70s2

I kind of had the impression that you used ER70s6 for your run of the mill mild steel and ER70s2 for things like 4130 tube.

Recently watching some video on YouTube a fellow was showing off his skills and welding up some mild steel welded square tube with ER70s2. I had just asked the manager over at the local Praxair store what the practical difference was, and he said basically what I said in the first sentence of this post.

So anyway, what is the real world general application of the two types of wire?

I know. I know. Go melt some wire and see what happens. LOL.

[danlb]

The S6 has more anti oxidizers. It's supposed to work better on certain alloys. I found this on AWS.org

from "https://app.aws.org/forum/topic_show.pl?tid=34126"

ER70S-2 and -6 are both A5.18, F6 electrodes, so one qualifies for the other without code restriction.
The differenes are:
S-2 electrodes are primarily used for single pass welding of killed, semi-killed and rimmed steels and are well suited for use in single side , melt thru welding without protective root shielding gas on the backside of the joint. S-2 has additional alloying elements of Ti, Zr and Al, plus lower levels of Mn and SI, as compared to S-6.

S-6 electrodes are intended for both single and multi pass welding . They are especially suited for sheet metal applications where smooth weld beads are desired, and structural and plate steels that have moderate amounts of rust or mill scale.

Both may be used for single or multi pass welding and on the same base metal classifications.

Dan

[Bob La Londe]

Thank you Dan.

[BigMike782]

S6 is generally used for MIG when there is minimal prep(mill scale) or LIGHT rust. S3 is generally used when the finished product will be powder coated(no/less silica islands)
I have seen S6 TIG filler but have always used S2.
All of this wire is 70,000 psi.
You want to have fun? ask 3 suspension fabricators in the same room which wire to use

[shawnspeed]

S6 will float out more impurities than S2... Since tig work is generally cleaner then mig , S-2 is the go to.... and my take on the suspension welders...ER80D6....LOL

[Bob La Londe]

Here in this video https://youtu.be/pJClB_2sz6E?t=234 he is laying in an open root pass with ER70S6 TIG wire in preparation for a 7018 cap pipe welding in the 2G position. The guys at Weld.com (source of the video) usually are spot on with their information. So how would he have made the choice to use ER70S6 for that application? Its well cleaned up in prep for the weld, so S6's ability to deal with a little mild scale etc would not have been a factor.

[LKeithR]

...You want to have fun? ask 3 suspension fabricators in the same room which wire to use...

Most of the chassis fabricators that I've encountered are pretty clueless; especially the younger ones that are
"internet savvy". They find a hero to emulate and as long as the "hero" says it's the proper technique or material
that's the only way they'll do something.

My brother and I have been tig welding for about 40 years and all we've ever used is ER70S6 filler rod. Unless you're
welding something where the filler is specifically identified--like certain pipe applications or aircraft work--no one will
be able to tell the difference. A really good fit up and perfectly clean material are far more important for 99 per cent
of the tig welds performed...

[danlb]

The production welders usually use approved welding procedures that are documented. If you follow procedures from the American Welding Society (AWS) Standards you will get a good weld every time.

The video in question will probably fall into one of 3 categories.
1) it was not real work, it was just a demonstration for the video so the filler choice did not matter.
2) It was a fab shop, and the AWS procedure for that type of weld specified that filler.
3) The engineer who designed the pipe specified it due to the choice of alloy in the pipe.