TIG Calculators

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In school, we did most of our welds on fairly low amperage and with small consumables. For example, a fillet joint made out of 1/4" mild steel flatbar had two passes, each with a 3/23" filler rod, at 75~100A (depending on whether or not the 8-pack was set right). If we'd been finishing them off, we'd have probably done two more. 1/8" tungsten (2% thoriated), gas thru the lens around 25 CFH, you get the idea.I fed that metal thickness into the TIG calculator on Miller's website, and it gave me vastly different results: 275 to almost 400A, and a 3/16" filler rod.So is the TIG calculator suggesting I do fewer passes at higher amperage and laying more filler, in the interests of saving time? Or is there something else going on here?Currently working as a Paralegal, but still interested in hobby welding.Miller Bobcat 225ntOne- Character Fractions: ¼ ½ ¾ ⅛ ⅜ ⅝ ⅞
Reply:I'm no expert, but I'd say your machine at school was wasting gas and the amperage was far too low to get good penetration in the one pass. With respect to the calculator, the Miller iPhone app doesn't suggest 400A:Neither does Lincoln's:For me, one of the beauties of TIG is the ability to set the machine at its maximum amperage, then work the pedal to make the puddle do what I want it to do. Turn up the machine and practice interpreting the metal's behavior.-Chris
Reply:Originally Posted by teh603In school, we did most of our welds on fairly low amperage and with small consumables. For example, a fillet joint made out of 1/4" mild steel flatbar had two passes, each with a 3/23" filler rod, at 75~100A (depending on whether or not the 8-pack was set right). If we'd been finishing them off, we'd have probably done two more. 1/8" tungsten (2% thoriated), gas thru the lens around 25 CFH, you get the idea.I fed that metal thickness into the TIG calculator on Miller's website, and it gave me vastly different results: 275 to almost 400A, and a 3/16" filler rod.So is the TIG calculator suggesting I do fewer passes at higher amperage and laying more filler, in the interests of saving time? Or is there something else going on here?
Reply:325 plus 33 (for mild steel) is 355. Close enough to 400.Edit: How do I delete a post? The one above came while I was typing this one.Last edited by teh603; 12-12-2015 at 01:13 PM.Currently working as a Paralegal, but still interested in hobby welding.Miller Bobcat 225ntOne- Character Fractions: ¼ ½ ¾ ⅛ ⅜ ⅝ ⅞
Reply:If your welding 1/4" steel with decent amount of mass or area try using 170-200 amps. Try 185-190 first and 3/32 or 1/16 filler if you can keep up. 25 cfh you can run a big 10 cup. The trick is getting a really close arc and pretty quick travel speed. Not too fast tho. That's what I do
Reply:Are we talking one-pass or multi-pass here?Currently working as a Paralegal, but still interested in hobby welding.Miller Bobcat 225ntOne- Character Fractions: ¼ ½ ¾ ⅛ ⅜ ⅝ ⅞
Reply:sorry but i keep thinking of pipe welder welding 1/4" thick pipe. obviously less amps and weld control is easier. i cannot remember seeing any pipe welder using over 100 amps tig welding pipe. .if you got a fillet weld and all bench welding all day long why even use tig and not mig weld ??.those charts showing tig welding 1/4" at 200 to 400 amps geez average air cooled tig torch max's out at 100 amps and gets too hot to hold after 10 minutes or less. got to be talking water cooled torch at least
Reply:I used to hit 230 amps with my ck17 torch. It was tough as nails!
Reply:Originally Posted by teh603Are we talking one-pass or multi-pass here?
Reply:and here i am, always thought the very best welders could weld with the least amperage and make the smallest welds and when doing sheet metal doing the least warpage.most welders i know rarely get over 100 amps with steel and stainless. sure might get up to 200 to 250 with aluminum. but usually if welding battleships and heavy plate you are spray arc mig welding or using 3/16 stick rod like 7018
Reply:Everyone has there own way. I'll weld 140 amps on a 1/8" lap joint and call it good. You just gota figure out what you like
Reply:speed is more important then amps. Lets see you copy me and see what you get. 1/8" mild steel
Reply:That's going to take a while, considering I don't have an argon bottle, regulators, or the right adapters to hook my torch up to the bobcat. Not that I'm unwilling to try- I just don't have the equipment right now and part of this thread was me being concerned about whether or not my torch (an SR-17FV) was up to the task.As for using MIG or not, for me that's a simple issue- I don't know enough about MIG to feel confident messing with it, while I do know a bit about TIG.Currently working as a Paralegal, but still interested in hobby welding.Miller Bobcat 225ntOne- Character Fractions: ¼ ½ ¾ ⅛ ⅜ ⅝ ⅞
Reply:Originally Posted by motolife313speed is more important then amps.
Reply:Great video by Jody on this topic. If you put together a scratch start setup, as long as you get the amperage close(guessing high is better than low) you can fix the rest with travel speed.1988 Big 50 Diesel CC/CV1982 Weldanpower 225/2101968 SAE 300 motor generatorMaxstar 200SD2015 AHP 200x"The trouble with our Liberal friends is not that they're ignorant; it's just that they know so much that isn't so." - Ronald Reagan
Reply:teh603.....I wouldn't be concerned about what the tig calculator says (there was even a question from a while back wondering if a 200 Dynasty was enough machine to weld pipe).  My belief is those high numbers are strictly for instant puddle start up and fully meant to be adjusted by foot pedal.    As previously stated, the example 1/4" mild steel piping gets welded all the time at 80-120 amps.  Am surprised machine companies don't more widely promote this feature for selling tig.  On stick and mig, soon as you strike up, a whole lot starts happening.  With tig, newbies can effectively weld at lower amps, watch your puddle develop, learn to dip and constant feed, widen your puddle and learn to fill a weave.  Doesn't take long, get a grasp on the basics, then you can progress onto the faster speeds for stainless and the complications of aluminum.Just to comment on this pic taken from the above video.  Wish the welder would have stated his amps but in any case it's a good example of a HAZ zone.  See how it grows from right to left.  On mild steel, it's no big deal.  If the weld was at all critical, he probably would have stopped in the middle, let cool a bit, then restarted on the left and finished in the center. Attached Images