Econo Tig on 1/4" mild steel

[jjense15]

Does my econotig have enough output to safely weld on 1/4" mild steel? I normally don't work on anything over 1/8" and am currently set up with a 3/32" tungsten and use 1/16" filler rod. I would go to a 1/8" tungsten with same diameter filler rod, and a larger gas cup.

Great board
Thanks,
Jason

[HAWK]

jjense15,

Your machine maxes out at 165 amps and has a duty cycle of 20% at 150 amps. You might get 3/16" mild steel pushing it hard wide open. If you can run a good bevel on both 1/4" plates and make 2 passes you might get it. A 200-300 degreee F preheat would also help you get the filler to lay in. Even at that you won't get a good structural weld. If you want to try a 3/32" zirconiated tungsten will withstand the heat. Don't preball the end. It will ball on its own under the heat running wide open. This will be very hard on the machine. You might run it a minute or less and let it cool between passes.

If you can stick weld it with a 1/8" 7018 or even a couple passes with a 3/32" 7018 you stand a better chance of penetration.

Just a few thoughts.

[Danny]

Jason,

You can TIG 1/4" steel with the Econotig, but you're going to have to use multiple passes. There is no need to step up to a 1/8" tungsten, the maximum output current on your Econotig in around 170 amps, and i would assume that you are using a 2% thoriated tungsten. The current range for a 3/32" diameter 2% thoriated tungsten is roughly 150 to 250 amps, so your 3/32" electrode will handle the maximum output of the Econotig with out any problem. For filler rod i would step up to a 3/32" or 1/8" ER70S-2. If you have to weld a large volume, the duty cyle of your machine could become an issue.

Now, if these welds on 1/4" steel are non-critical, it is possible that you won t need the full size weld on the 1/4" material. So a smaller single pass might have adequate strength. I just depends on what this thicker material is being used for.

BTW,don't forget, that your unit is also a stick machine.

[jjense15]

Thanks Dan and Hawk. I have to do some structural mods to my enclosed car trailer. I think I will bring the trailer to work and use our Millermatic 300 MIG, probably better suited for the job anyway. Suggestions on machine set-up? Have not MIG welded in a while.

Thanks again,
Jason

[Danny]

Jason,
If we,re looking at structural welds on 1/4" steel that can be performed in the flat or horizontal position, I d weld the joints out in spray transfer mode. For spray transfer, i prefer to use 98% argon/ 2% oxy for my shielding gas. 90% argon/ 10 CO2 is another gas mix that I ve started using lately. Mainly i stick with the 98/2 because it allows me to spray arc steel or stainless steel. The 90/10 actually produces a better penetration profile then the 98/2. However, i haven t had a single weld fail in 15 years using 98/2 for spray transfer. Anyway, for wire I d use an .035 E70S-6. Then i d set the machine to output around 24 to 25 load volts and about 200 to 210 amps. This amperage range roughly translates into 400 to 420 IPM of .035 wire being fed.

[cope]

Originally posted by Dan
Jason,
If we,re looking at structural welds on 1/4" steel that can be performed in the flat or horizontal position, I d weld the joints out in spray transfer mode. For spray transfer, i prefer to use 98% argon/ 2% oxy for my shielding gas. 90% argon/ 10 CO2 is another gas mix that I ve started using lately. Mainly i stick with the 98/2 because it allows me to spray arc steel or stainless steel. The 90/10 actually produces a better penetration profile then the 98/2. However, i haven t had a single weld fail in 15 years using 98/2 for spray transfer. Anyway, for wire I d use an .035 E70S-6. Then i d set the machine to output around 24 to 25 load volts and about 200 to 210 amps. This amperage range roughly translates into 400 to 420 IPM of .035 wire being fed.

Dan, Which machine are you running 90/10 on? I bought a cylinder of it for my PowCon but I haven't tried it yet. I am afraid to do much spray with the #1 Tweco gun I have now. Scottt is sending me an Esab Gunmaster 250 and I think it will be a little better for spray.

[HAWK]

cope,

I am using a 92%argon/8%CO2 mix with a 250 amp Bernard gun and .035 ER70S-6 wire at 28 volts around 340IPM on wire speed. It seems to do best with near a 3/4" stick out. The 92/8 is a bit hotter gas than the 90/10, but also gives less penetration with short arc due to its lower CO2 content. 90/10 is not prevalent in the east TN area. I also use it for short arc, but have a 400 amp GMAW power source to overcome the lesser penetration issue. Sometimes a larger wire and globular transfer is the answer, but typically stretch the limits on .035" wire ans short arc.

[cope]

Originally posted by HAWK
cope,

I am using a 92%argon/8%CO2 mix with a 250 amp Bernard gun and .035 ER70S-6 wire at 28 volts around 340IPM on wire speed. It seems to do best with near a 3/4" stick out. The 92/8 is a bit hotter gas than the 90/10, but also gives less penetration with short arc due to its lower CO2 content. 90/10 is not prevalent in the east TN area. I also use it for short arc, but have a 400 amp GMAW power source to overcome the lesser penetration issue. Sometimes a larger wire and globular transfer is the answer, but typically stretch the limits on .035" wire ans short arc.

90/10 isn't available on every street corner in Houston either. I have a havier gun coming which sould let me spray easier. My Tweco #1 is a bit light for upper end work. The one I'm getting is an ESAB Gun Master 250. I will have the option to set the tip recessed, flush or with stickout; something lacking on the Mini-Mig and #1 Tweco.