TIG vs. Stick - Maximum material thickness

Hi all,
I'm in the process of getting a used TIG welder running. It (a Powcon
300ST) will also do stick welding, and I'm wondering if using this machine
as a stick welder will allow me to weld thicker pieces of material than it
would while using it as a TIG machine. I'm assuming that using it as a
stick machine will be faster than using it as a TIG...
I got it for TIG use but if it has expanded utility as stick machine, that
would be a cool thing.
Peter
Reply to
Peter Grey
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You can weld unlimited thickness either way. TIG will be slower, Stick faster.
A Powcon 300 can run 5/32" 7018 stick rod all day long at 170 amps. You can weld 1/2", 1" or even 2" plate steel. It just takes time to lay in all those passes.
Reply to
Ernie Leimkuhler
Ernie,
Is the maximum thickness per pass the same for TIG and stick?
BTW, could I weld 1" steel plate with my Lincoln 135 by doing multiple passes or is there just not enough power there to heat up the surrounding metal?
Thanks,
Peter
Reply to
Peter Grey
If you vee out the plate and work your way up, you can weld 1" plate with a 110V machine. You need to tie each pass into everything it touches - the previous passes and the side of the groove.
Reply to
Rich Jones
This is a tough one to answer, because the answer is no, you can't run thicker material with stick than with TIG, but the reason id that you really don't have a limit on thickness. How much time are you willing to spend to do the job?
TIG is generally slower than stick for a given weld, but can give a much better weld than stick in many circumstances, and is much more versatile. TIG is tougher and slower to lay in a given ammount of metal, and stick usually will lay the metal in with less current (but not necessarily less total energy, as the the voltage on the stick arc is usually higher-- the energy to meat 1g of filler and base metal is the same no matter what process) but the control TIG gives, as well as the ability to run materials stick really can't do well, more than make up the difference.
Butt welding thick material is a toss up: If the material is thick enough, you need to multipass with either process, with bevel or other open prep. If you can butt and fuse the material, TIG is the winner by fer due to reduced prep and filler cost, and a TIG pass won't be much slower than a stick pass. The general rule for TIG on carbon steel is about 1000A per inch of thickness in a single pass, so at 250A, you can run about 1/4 inch material. Stick is lower current (as the filler is the electrode), but you are stuck with leaving a place for the filler to go, increasing prep time and cost.
For a given machine current, stick will let you get thicker material in one pass, especially with fillet welds, but the question should really be "which is faster" or "which costs less if I can control te prep" or " which goves moe control ober the total heat" or any number of others you will discover with practice.
Reply to
e
Peter, in addition to what Ernie and some of the other guys have said, let me tell you what I know about the POWCONS - first, you have to ensure you have it set PROPERLY for 230 volts single phase, or you'll damage it worse than you can imagine. You also have to have the wires wired properly - per the manual. You have to follow the label plates inside precisely, and there are 3 positions, IIRC that have to be changed. Second, running POWCONS on 230 will not, IIRC, give you the same output and duty cycle that they are rated for on 450V 3 phase.
It will weld thick metal with huge rods all day long, on 450v 3phase, but on 230 single phase, they have a tendency to eat electrolytic caps - be warned. I don't try to overdo it with mine - but I'm only running 7018 most of the time and not a lot at any one time. Hope this helps.... Steve
Reply to
SPR
Yep. I'm checking that. My 5 HP RPC isn't big enough to power the welder so I'm going to make sure it's wired properly fo 230 single phase. If I get a big RPC, maybe I'll change it to 230 three phase. I did buy the manual and will follow the wiring instructions.
Thanks. I was asking about how thick a piece I can weld mostly for my education. I'm having a hard time seeing myself welding anything thicker than .250 and most will be much thinner than that.
Peter
Reply to
Peter Grey
No. It is dependant on how you do it.
You could lay in lots of small passes running 3/32" 7018, or fewer passes rinning 5/32" 7018.
You could TIG weld it down at 100 amps, and really take your time, or run it at 200 amps and get there quicker with a little more distortion.
I have welded 1" plate with a Hobart Handler 120. However I did a lot of "tricks", to get away with it.
1. V-grind your joint so there is a 90 deg Inclded angle with a 1/16" land at the bottom and a 1/16" root gap, and no backing strip. 2. Preheat the plate to about 500 degF, and reheat it before each pass. 3. Run 0.024" wire with C25 gas 4. Lay in each pass at the maximum power with a slow, narrow, weaving motion. 5. Let the machine cool down for 15 minutes between passes.
Reply to
Ernie Leimkuhler
snip
Sure makes for a LOOOONG day!!!
Reply to
Roy J
I was proving it could be done, not setting up for a production run.
Reply to
Ernie Leimkuhler
What did you preheat the metal with?
Peter
Reply to
Peter Grey
Oxy-Propane rosebud torch.
Reply to
Ernie Leimkuhler
What sort of testing did you do on the finished weld? Did you discover any problems anywhere in the layers?
Reply to
Andrew Hollis Wakefield
I treated it just like any WABO Certification (Washington Assoc of Building Officers). I cut 2 coupons from the piece and bent them in the approved press die. No defects. The welds passed.
Reply to
Ernie Leimkuhler

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