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Discussion Starter #1 (Edited)
I have been wanting to learn to tig weld for quite some time. So recently I bought a used but very nice Lincoln tig 255. The adjustability on this thing is almost infinite and thats probably making it harder.

I've been practicing on 1/8" steel with my machine set on 2-step and have had pusler on and off with mixed results. Been trying everything between 40 and 50 amps. has foot pedal control. Using aircooled torch. Problem is that it seems to be overheating the tungsten after a couple minutes and I get erratic arcing. using 3/32" lanthanated tungsten. I'm grinding it properly too.

So far I've made some decent amatuer looking welds. Hoping you guys can help me take out some of the mystery.

Aaron
 

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I run my 3/32 tungstens as high as 125/150 amps sometimes without much problem..... I am wondering what polarity you are using?

If you use straight polarity you will see a ton of heat in the electrode. You should be using reverse.

dkp
 

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Discussion Starter #6
DC- or DCEN

How far out should the tungsten be. I had my gas around 40scfh
 

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Discussion Starter #8
I started at 80a and it really heats up the metal fast so I started turning it down in an attempt to control the heat I was putting into it.

I'll bring it up and just try to move faster

Should I be using the pulser? is it for certain applications or is it preference. I figured it would help limit the heat absorbed by the metal but I've only tried it on a couple passes.
 

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Discussion Starter #10
What shielding gas are you guys using? I have 75/25 argon/CO.
I am getting a pretty decent weld now but the metal seams dark and oxidized. I thought it should be shinier like when you chip the flux off of a good stick pass.
wondering if the gas is my problem?

all questions are related to welding plain carbon steel.

Aaron
 

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What shielding gas are you guys using? I have 75/25 argon/CO.
I am getting a pretty decent weld now but the metal seams dark and oxidized. I thought it should be shinier like when you chip the flux off of a good stick pass.
wondering if the gas is my problem?

all questions are related to welding plain carbon steel.

Aaron
Co2 (straight or mix) is fine for Mig welding mild steel, but not Tig. Probably part of the reason why the weld looks "dark and oxidized". Go with the straight Argon for Tig welding mild steel & 'moly, and adjust the machine to allow some amount of gas post flow time after the finish of each weld pass.

Depending on the weld joint type/layout/design/fit-up I usually use a .0625" (1/16") 2% Tungsten & a small #4 cup on most everything ms & cm up to about .134" thick material (and sometimes thicker material). And usually the .09375" (3/32") tungsten on .1875" thick & thicker material, (or where I have to use a bigger OD filler rod than normal).
 

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x2 on the shielding gas. ditch the co2. there is no place in tig welding for co2. argon is the was to go. there is also argon helium mix. in my shop i use pure argon on everything. we do production aluminum and stainless fabrication.

keep the 2% lanthanated 3/32 with about a 3/16 stick out. and try a number 4 or 5 cup and run your shielding gas volume around 20cfh in a wind free environment. (tig welding does not work in the wind) i would also turn the pulser off till you really get the hang of things. i would also be running in the area of 75-80 amps. make sure you have the start high frequency set to start and be running on DCEN. also make sure that you are working with clean material. ie. no mill scale or oils on the surface.

if you cover all of these things and are able to keep the tungsten out of the puddle then things should go really easy.


barry
 

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Discussion Starter #17
got the pure argon today, tried steel and aluminum. much better on the steel and the aluminum was surprisingly easier to weld IMO.
 

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Discussion Starter #18
So lately I've been practicing more on aluminum and mostly it just produces lots of 4 letter words. What am I doing wrong.

Yes, its clean. Like carbide burr and stainless wire brush. Have tried pure tungsten from .040-1/8 and from 80 amp to 180 amp. auto balance and manual balance.

I'm even cleaning my filler rod with a scotchbrite pad.

I cant quite seem to get over the hump.

Please help:confused:
 

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I am no expert by any means. Basically self taught. A couple things that I found helped me. Keep the filler rod well clear of the arc until you are ready to dip it in then pull it all the way out again. Seems to keep the temp of the rod down and gives you more time to get it where you want it. Also keep the heat as low as you can. Just enough and you will find that you will need less and less as the pass progresses and the full piece of material heats up.

Another thing I find is that the gaps need to be tight or the air will come in from the back side and contaminate your weld.

I have been messing with it for several years and still struggle at times. Pisses me off when I buy a new aluminum pan or something and I see these beautiful perfect stack of dimes aluminum welds. :eek:

Pretty sure a lot of that stuff is done on machines with pulse and auto feed filler rods. At least thats what I tell myself to ease the pain. :D

dkp
 

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Does you foot control,control the amps to some have a switch to flip for panel or remote on amps. Haven't used a linc just miller i know on the miller one of ours has the switch and the other one don't.If yours does have the switch you smash all the way down for your max amps you have it set on as you let up on it it will reduce the amps some.When the metal or alum starts getting hotter from the weld you will need to reduce the heat by letting up on the foot padel alittle. yes the 100% argon is the best.

Jim
 
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