TIG welding 101

[98Camarod]

Any pointers? I was playing with it today and I don't know if there's something fucked up with the gas delivery or I'm just that terrible. I was able to run some lines without filler metal and some with filler metal. It's pretty cool and I had fun doing it, but I suck.

When you initially press the pedal down to try and lay a bead with it, pretty often it didn't want to arc correctly. I'm not a professional by any means, but it seemed like the there was too much gas. But then if you waited a few secs or tried it several more times it would work. It also seemed like if I tapped the pedal before trying to weld to get the gas flowing it appeared to help.

I have the amps set at 50ish and it seemed to work ok. It was initially at 160 and it burnt right through the pipe:mrgreen: If you notice, I have said seemed quite a bit, that's because I don't know what the fuck I'm talking about

[DolSVT00]

I'd have to look at the machine settings, but it sounds like you have a couple of them wrong or you have something on the tungenstone. What kind of material are you welding? How is your ground connected? How have you got the high frequency start set? How is the arc control set? Do you have a postflow setting? What kind of tungenstone are you using (2%,pure, ect) Are you using a gas lens or a diffuser (collet body)?

There are alot of variables in why it could do as you described, if your grounding is not true it will meander, if your part is ferrious, magnetisim will cause meander. Gas flow should be simple, set it where the top of ball is at 35-40 CFH when you press and hold the pedal. If its aluminum that your welding cup position (arc control) means alot, example if the wire starts melting befor it gets to the puddle , you have too much arc angle.

[Harry]

Get a Book. They have them at Books a Million.

[BAD BOB]

mine is usally around 100 for the max setting bc you can always use the pedal to controll between that. it sounds like it wont arc bc of low power. i usually push the pedal a little harder then needed then back off as soon as the arc happens. im not an expert either but it works. tig is alot harder than mig so it will take some time learning. gas on mine is around 20psi i believe

[Mustangscotty]

I went to youtube and a few weld manufacturer websites and watched video's. Seemed to help me the most.


http://www.youtube.com/results?search_query=how+to+tig+weld&search_type=&aq=f

http://www.lincolnwelding.com/knowledge/articles/list.asp

http://www.instructables.com/id/How-to-Weld-TIG/

http://www.weldingtipsandtricks.com/

[98Camarod]

It's pure Tungsten, I bought a new 25' lead and grounded it to the pipe. It's 3" aluminum pipe. There are only two knobs on this, one for amperage and one for weld cleanliness/penetration which I have it set to the max cleanliness part.

[98Camarod]

I went to youtube and a few weld manufacturer websites and watched video's. Seemed to help me the most.


http://www.youtube.com/results?search_query=how+to+tig+weld&search_type=&aq=f

http://www.lincolnwelding.com/knowledge/articles/list.asp

http://www.instructables.com/id/How-to-Weld-TIG/

http://www.weldingtipsandtricks.com/

I went through a few of the videos, which is why I "knew" how to begin

[Mustangscotty]

Knowing how to begin is the easy part. I assume the trouble shooting for a process is what your after. I understand that part.. Looking at the video's closely is where the answer is. Good luck, remember "dime at a time".

[gearmesh, inc.]

It's pure Tungsten, I bought a new 25' lead and grounded it to the pipe. It's 3" aluminum pipe. There are only two knobs on this, one for amperage and one for weld cleanliness/penetration which I have it set to the max cleanliness part.

That knob for cleanliness/penetration sounds like a balance control. When A/C tig welding aluminum, the positive half of the A/C cycle is for cleaning, and the negative half is for penetration. The balance control will offset your polarity crossover zero line up or down into either the positive or negative range to increase either the cleaning or penetration characteristics. By you setting the knob to max cleanliness, your penetration is at a minimum. This can be beneficial when you are working with thin material to avoid burn through. It also makes for a wider, shallower bead. Of course, when your cleanliness is at maximum, your tungsten is seeing more heat because it is at a positive polarity for a longer period of time vs. the time it spends on negative polarity. Depending on the amperage you need to make a puddle, you may need to bump up to the next diameter tungsten to deal with the extra heat the tungsten will have to put up with when your balance control is set to favor the cleanliness side.

In any welding process, the positive polarity part of the setup will have 70% of the heat with it. When your ground is positive, 70% of the heat is in your workpiece and 30% is in your negative polarity electrode (tungsten when tig welding). This is what gives you penetration because the workpiece is hotter. When the electrode is positive, 70% of the heat is in it, with 30% in your negative workpiece.

AC is needed when tig welding aluminum due to the need for the cleaning half cycle since aluminum oxidizes so fast. The other half cycle is for penetration. Aluminum tig welding is a bitch compared to the ease of tig welding carbon or stainless. One little spec of carbon or foreign matter in your puddle will make the puddle run from the impurity. The only thing you can do is grind the impurity out and try again.

Carbon steel and Stainless are normally tig welded with DC electrode negative polarity for excellent penetration and a cooler tungsten. You have much more control with putting the arc exactly where you want it with DC tig, too, as the sharp point on the tungsten won't melt into a ball since the electrode is always negative. This sharp point is what gives you excellent control of your arc. You have no choice with AC tig, as the tungsten is positive polarity part of the time and has more heat in it.

It is normal practice with AC tig to maintain a ball on the tip of your tungsten. You usually try to not let the ball diameter to exceed the diameter of the tungsten. If it does, the tungsten is getting too hot and you need to go to the next bigger diameter tungsten.

The longer your electrode lead is, the effectiveness of high frequency start may suffer with it. Try and see if a shorter lead will improve your arc starting difficulties. Helium, although more expensive than argon, works better with aluminum as a shielding gas, too. Avoid tig or mig welding in windy areas, too, as your shielding gas will get blown away.

[98Camarod]

One little spec of carbon or foreign matter in your puddle will make the puddle run from the impurity.

It is normal practice with AC tig to maintain a ball on the tip of your tungsten. You usually try to not let the ball diameter to exceed the diameter of the tungsten. If it does, the tungsten is getting too hot and you need to go to the next bigger diameter tungsten.


I noticed that while practicing. While I couldn't see anything wrong with the metal, but the puddle could apparently.

As for the ball, I read that it was supposed to be there for aluminum, but I'm not sure how to make the initial ball when inserting a new piece of tungsten.

I'm using 3/32 right now. For some reason the tungsten fell out once. I waited for it to cool down and closed the tip more to hold the tungsten in and didn't have a problem after that.

[BAD BOB]

grind the tungstun to a point then turn the machine to where you arc weld dc+ i think and holt the torch with the tung in it about a 1/4 inch away from a piece of clean steel and hit the pedal for just a few seconds and it will basically melt the tip into a ball

[98Camarod]

grind the tungstun to a point then turn the machine to where you arc weld dc+ i think and holt the torch with the tung in it about a 1/4 inch away from a piece of clean steel and hit the pedal for just a few seconds and it will basically melt the tip into a ball

Ah, I didn't know you had to grind it to a point for the ball also. I just did what you said without grinding to a tip and it worked that way also.

[98Camarod]

I did some more practice and I can make a bead pretty nicely, but I can't weld two pieces together for shit.

I got curious with the settings so I had the wife read the V when I pressed the pedal down. For welding the beads that I did, I had it set to 45 A and when I started it went to 23V and came down to 17V after I let off and started the bead. So I cranked it up to 130A to see what it read and it only went up to 48V and came down to 24V. It definitely melted a hole through the aluminum on the higher setting. Does that sound right for the V for the A setting? I'm assuming the A is for amperage and the V is for voltage.

[BAD BOB]

mine is set at i think 110 for alum. i would suggest starting with welding steel first just to get the hang of the pedal control. when you are welding 2 diff objects together the heat transfer is different bc they are 2 separate pieces where when you lay a bead ontop of the single piece all the heat is right there. when welding aluminum, it is easier when it is hot as if you started welding and you will see as you go on it gets easier bc you are basically preheating the metal by welding. aluminum is prolly the hardest you will weld bc of its melting point. it will liquify without notice almost. when i learned is started with steel then went to aluminum and went through many filler rods and had to regrind the tungstun alot. when doing the alum start like you have with just laying a bead then try welding some pieces overlapping each other then try welding two side by side

[98Camarod]

^^What does your voltage change to? I'm just trying to make sure the unit is solid and I'm the fucked up part, not the machine.

I'm patient. I don't expect myself to be able to weld perfectly in a month of practice. I figured learning on aluminum would make everything else a breeze.

I don't have any metal to practice on either besides this aluminum. I did buy filler rod for aluminum, SS and mild steel though

[98Camarod]

Randy is my hero. Thanks again for the tips, tricks, and help

[gearmesh, inc.]

Your open circuit voltage will always be higher than the actual voltage at the puddle after you start the arc. The voltage at the arc won't vary much at all with different amperage settings, but the amperage is what is making the heat.

As far as getting the ball on the tungsten for AC tig, I just chuck up a fresh piece with its square end right out the box and it will ball up just nice when you feed it enough amps. To redress a contaminated tungsten, I just break the bad part off and strike an arc to automatically ball up the raw end again. This is how I was taught to do it. Me personally, I wouldn't go to the trouble of grinding a point suitable for DC tig just to melt it into a ball end when I am AC tigging aluminum. Melting an already pointed end may cause a drop of tungsten to fall off into the puddle on your workpiece. Then you have to grind this "impurity" out to make your weld right.

If you haven't been introduced to the different tungstens out there, use only the green color coded pure tungsten for aluminum. The red tungsten is thoriated tungsten which is used on carbon and stainless steel.

[gearmesh, inc.]

Oh, yeah, on the subject of welding two pieces together on a butt joint, you have to move your tig torch from one side of the joint to the other. I usually start off on one side, start a puddle there, add a little filler, and then move the torch over to the other side of the joint to get that side melted. Once the other side melts, you will see capillary action take place and the puddle will drag itself over and become melted with both sides of your joint. As you continue with your bead, alternate from one side of the joint to the other just a little to make sure both sides get melted in. Use a zig-zag pattern so you advance yourself down the joint. Butt welds take some practice because a just a little too much heat will have your burning right through due to the air gap between the two pieces having zero heat sinking properties. Be prepared to slack off on your foot pedal as you workpiece heats up, so that you avoid your puddle getting too hot and dropping through. At the end of your weld, ramp down the amperage slowly to avoid a crater and the accompanying crater cracks.

After you stop the arc, keep your torch in place for a few seconds so that the shielding gas will keep flowing to keep contaminants out the puddle as it solidifies. Some tig machines have a post flow timer you can set for how long you want this after purge to last. Most low end machines have a fixed timer of about 10-20 seconds.

A good practice drill on welding two pieces together is to do a lap joint first. You won't really have to worry about burning through, so you can concentrate on getting the hang of melting both sides together.

[98Camarod]

Thanks for the info! Randy actually came over and showed me a few things, mainly what I was doing wrong. Once he showed me the correct way it was a breeze.