TIG wire, S2 vs. S6

[JoshD]

I got an order delivered today and one of the items I ordered was ER70 S2 wire. Instead they sent S6 wire. Is there much of a practical difference between the 2? I have used the S6 for MIG of course, but the only TIG wire I've used so far is E80S D2.

Its not a big deal as it was only 1lb, but what characteristics does S2 have that make it preferable to S6 for TIG? I see S2 recommended often but rarely S6 unless you are stripping it off a roll when you get in a bind.

[zapster]

S-6 will give you a "harder" weld compared to S-2..

Just a little difference in machinability..

...zap!

[JoshD]

Thanks Zap, sounds like it won't make any difference either way for my use at this time.

[Supe]

The S6 is a more fluid puddle. The "fisheye" is typically larger as well (the silicon island that floats to the top). On our construction sites, most welders prefer the S6 wire as the increase in silicon content reduces porosity.

[MoonRise]

S6 filler has a little more deoxidizers, especially silicon, than S2 filler.

So you get a bit more of the silicon islands in the weld bead with S6 filler than with S2 filler, but you also have a little (note LITTLE) more tolerance (note TOLERANCE) for 'crud' in the base metal as well. Note that TIG 'tolerates' about the least amount of 'crud' of all the arc-welding processes (compared to SMAW, GMAW, FCAW, or SAW).

And the slightly higher silicon content in the S6 filler also gives a slightly more fluid puddle than the S2 filler.

[ByThePiece]

The s2 is more trashy than s6, Any pipe and heater work I've welded going to Alaska particularly North Slope is all welded with S2. Inspectors tell me its a softer weld than s6. Hope this helps.