Welding Tips and Tricks

Hey everyone. I just got a Lincoln Squarewave TIG 200. I got it set up and did some welding with it today. I've done very little tig welding so I'm trying start the learning process. I had a few problems today and wanted to get some advice. I was welding some 1/8 mild steel on DCEN. I was using a 3/32 2% lanthanated electrode ground to a point, #7 stubby cup with a gas lens, 3/32 ER70S-2 filler. I had my machine set to 120 amps, using a foot pedal, and my argon was set anywhere between 15-20 ch. My first complaint was that my arc seemed to be wondering pretty bad. When I introduced the filler rod, the arc starts wondering even worse, and arc starts producing some sparks and leaves quite a bit of soot. Do you think this might be a gas flow problem? When I turn my gas off and bleed off the gas, the gas seems to be flowing kind of slow and erratic. But who knows, maybe all the problems are just because I'm a beginner. Any help is much appreciated!

A few things to check, easy to get wrong when new to tig.

Make sure you run DCEN, torch to negative and ground clamp to positive.

Check that you have pure argon In the bottle, no CO2 mix.

Check for leaks. High pressure should stay high when you shut the tank valve. Low side can be checked in many ways but soap water is reliable, no bubbles anywhere when gas valve is open and you block the cup.

Tungsten must be ground so you have grinding marks running along the taper to avoid wandering arc.

Set post gas to 5 s, light up until you see a puddle. Then cut off arc and keep torch steady until post gas stops. Both puddle and tungsten should still be silver color. Otherwise you have a gas issue.

Check flowrate with a pee-shooter so you know what rate exiting the cup. Sometimes the collet bulge and block the gas.

Both filler and metal must be clean and rust free. Mill scale to be removed. Tig is lot more sensitive to dirt than mig.

I have the same machine, the fan on that thing blows like a white house intern. So if you have the machine next to you when you're welding, it can blow the gas coverage away and cause a problem. Make sure you point the exhaust fan away from your welding area. I can't think of anything else that Anders didn't mention, that's a pretty complete list.

Also make sure you're not using a magnet near your welding pieces to hold them in place. They will cause havoc with your arc.

Only other thing I can add is to keep a short arc.


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christiankeith90 wrote:My first complaint was that my arc seemed to be wondering pretty bad. When I introduced the filler rod, the arc starts wondering even worse, and arc starts producing some sparks and leaves quite a bit of soot.

If you have too long an arc and perhaps a tendency to lift the torch as you add filler, this would cause the arc to wander

Thanks guys! I will keep working on everything and let you know how it goes. MarkL, how do you like the squarewave?

christiankeith90 wrote: MarkL, how do you like the squarewave?

I'm very happy with it. I've done a mix of steel, SS and Alum, I probably have 40-50 hours on it. Features I would like to have, or that I don't like are:
* The arc start is harsh. It starts about 25A then quickly drops to 10A to stabilize the arc, then gives control to foot pedal. Not sure why they did this, it's especially annoying on really thin stuff.
* The pre and post flow aren't adjustable. Post flow seems to be about 1s/10A. I generally like to leave the machine at 200A so I have the power to do quick tacks, but that eats up a bit of argon.
* Pulse frequency only goes to 20. My brain can only handle frequencies below 2 or above 30-40, so most of the frequency range isn't useable.
* No control over pulse %on or background, but the settings they programmed in work well for most things
* Exhaust fan blows out the front edges of the sides, so if I pull the machine close to where I'm working I have to point it the right direction or it blows the shielding gas away. I'd prefer it blew out the back, or at least the rear edges of the sides.
* AC frequency range is only 150, but that's not a big deal for me

It sounds like a lot of griping, but the list of things I like is much longer, so overall it was a very good purchase for my needs. It's very high quality and good finish, the foot pedal is really smooth which is often a piece of junk on less expensive machines. The torch is well made and has a good quality cover on it. Connectors are all well made and easy to work.

AndersK, I did exactly what you said and this is what I got. (Picture attached)

You definitely have a shielding problem. Go back to square one.
100%argon?
Regulator in good working condition?
Gas hoses in good condition?
Checked gas connections with soapy water for leaks?
Connections are made with no Teflon tape and tightened appropriately?
Gas exit from machine to torch is sound?
Hose to torch is secured?
Torch condition is not compromised?
Back cap condition?
Proper collet body and collet in correct orientation?
Teflon insulator on torch installed, correct type, and installed properly?
Gas nozzle seated?

Are your cables reversed?

Your original post mentions that you're using a gas lens. Have you ever used this lens successfully or is it brand new? If you've never used it successfully, put the standard collet body back on that came with the machine and try that. I've had gas lenses that stop working for reasons I've never figured out. Also if it's a cheap lens from eChinaBay, that might be the problem even if it's brand new.

How much of your tungsten is sticking out of the cup.

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It was a bad regulator! Hooked another regulator up and the gas flowed perfectly. I didn't have any time to weld but I can't wait to try it with good gas flow lol

Great, now the fun part begins

christiankeith90 wrote:It was a bad regulator!

Is that the regulator that came with the machine? That should be warrantied if it is.

christiankeith90 wrote:It was a bad regulator! Hooked another regulator up and the gas flowed perfectly. I didn't have any time to weld but I can't wait to try it with good gas flow lol

Nice. Got it on Guess #2!

Yeah, they replaced it for free. Thanks guys

Hi, I have also got a square wave TIG 200 which was bought by my uncle. In fact, I am a beginner in this. My main intention to study welding is that to repair my car that was actually used by my grandpa. I just want to keep that for his memory. Now it is in a damaged condition. I have to do some works for the door,fender etc. But my friend suggested to seek the help of a steel fabrication company in Toronto and am planning to get their help. I am actually fed up with the welding process at times. Beginners have to be cautious of such stuff. It is high time that I have to learn this more.

Warrenh wrote:How much of your tungsten is sticking out of the cup.

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I know this post is kinda old and the problem has already been fixed, but I thought I'd add my 2 cents. Besides technique, the 3 hardware mistakes I see my students make most often is 1st, like Warrenh mentioned, they stick the tungsten out too far. Text books will tell you the stickout should be 1-2 times the diameter of the tungsten. With regular hardware on mild steel though, you can easily get away with a 1/4" stickout, gas lenses of course offer more. The other two common mistakes I see is students will put the collet on backwards which blocks the gas completely, OR they will screw the back cap on first, which causes the collet body to only screw in 1-2 turns, causing clearance issues and gas issues.