Help, TIG

[Sundown]

I finnally connected with my neighbor (who has the Lincoln square wave 175) and he has agreeded to let me play with his TIG machine. I have never touched one and I was hopeing to get some hints to help me not look like a complete dumbo. We will do this first part of next week and any help or hints would be greatly appreciated. In the meantime I will study the Miller TIG education book a few times...

[Steel Butcher]

If you have done oxy/acet. welding before, you should be able to pick up TIG without much trouble.

[Sundown]

Nope, no O/A expierence. Started with MIG then did some SMAW with a AC/DC Hobart. Thanks anyway...

[Roger]

TIG welding requires torch arc control beyond your welding experence, holding 1/8” arc with one hand while feeding filler with other hand. Oxy/Acetylene teaches torch control while feeding filler. But, O/A weldors often fine tune heat to puddle by changing flame distance while TIG uses foot or hand amptrol. So O/A welding experience doesn't directly transfer.

Start out TIG welding practice just learning to start and hold tight arc. Then form and control puddle with amptrol pushing puddle along flat plate for 4” forming a consistent width bead. Must not touch tungsten to puddle. Practice until this is easy.

Next practice pushing puddle along butt joint with no gap to very slight gap until that is easy.

Then go back to making beads on plate only now your rhythmically adding filler to leading edge of puddle as bead is formed. Must keep rod in shielding gas and don't touch tungsten. Get good consistnent beads and your ready for first butt welds then fillet welds.

Too many details to cover which instructor and your reading will cover.

Search this site for “TIG torch exercise” posted by Roger. Will find decent thread on learning TIG.

[Dan]

George,

I d start you out on some 1/8" or 3/16" steel or stainless steel. This thicker material makes things occur a little slower, which gives you more time to evaluate everything that is going on.


Torch angle is real important. To much angle and your gas coverage and weld bead become long and narrow.

Im posted a couple stainless steel weld beads for you. I wish this first picture would have turned out better. I was trying to show you the color of a good stainless weld. The actual color of this weld bead is a very light gold color with some areas that are silver. The silver color is ideal but gold is good too. Actually on food processing equipment that I weld on blue is acceptable too.

Also, from this picture you should be able to tell how narrow the HAZ can be on a TIG weld.

The final thing that I m trying to show you with this picture is the notch in the end of the weld bead that i have marked with the arrow. This notch indicates that I don t have fusion to the root of the weld at that point. When you see this notch, either give the weld a litttle more current or just wait a little longer for this notch to disapear. Once the notch disappears you should have fusion to the root, and then you can continue forward with the weld.

Just thought of one other thing. Another problem that too much torch angle creates is that it preheats the filler rod to much and can cause it to ball up on the end of the filler rod when you try adding filler to the weld puddle.

Also, if you are going to be welding aluminum, I suggest skipping the balling of the tungsten. Just sharpen the electrode the same way as you would for steel or SS. Once you start welding the end of the electrode will ball some. However, this smaller ball creates a more focused arc that give you better control over the weld puddle then the balling technique that is generally recommended for a transformer based machine when welding aluminum. Im still trying to figure out why the balling technique is suggested

[Dan]

This second picture just shows you what a SS weld can look like after you brush off the weld with a SS tooth brush



BTW, George what happen to your New Mexico Lobos?

[Henro]

Dan,

Thanks for posting those pictures...as always!

66chevelle396

Here is a link to that thread that includes the practice exercise posted by Roger

Edit: Whoops! I see you already have seen it...well, the link still works if anyone else wants to take a look...

On second edit...just to prove I'm not confused... ... Sundown perhaps you haven't seen it after all... Not sure why I got you confused with 66chevelle396...

[customwelds]

Mmmmmm...PRETTY BEAD...*drools* haha, seems like you've gotten really good TIG info, and an AWESOME pic of a bead, have fun with it, TIG is GREAT to weld with!

[Sundown]

Roger, Dan...Thanks very much of the info and Dan the pictures will help alot. We are going to start out on 1/8" steel, I plan on taking it real slow and learning what I can while he is willing to teach me. I think that I can get a TIG class next semister at the local community college, I'm going to check after the new year starts. If not, I think that I will be able to in the summer for sure.

Dan,

The Lobos mostly play like that , I have to say that your team is much better than I had heard, those guys made the lobos look like they were standing in mud. Glad to hear you are up and about, the flu is the pits. And thanks again for the pictures and knowledge...

[2gofaster]

Excellent info, Dan. I've got a question for you. I'm welding .063 304 tubing now. If I fuse it together, I can get that nice gold color. But where I use 308 filler rod, it turns to a dark grey with the same machine settings. Am I doing something wrong?

[bishopaul]

dan, you the MAN! i know i need practice, practice, practice, but that bead is ridiculous....

[Dan]

Originally posted by 2gofaster
Excellent info, Dan. I've got a question for you. I'm welding .063 304 tubing now. If I fuse it together, I can get that nice gold color. But where I use 308 filler rod, it turns to a dark grey with the same machine settings. Am I doing something wrong?

shane,

The addition of filler metal general requires a little more current then just fusing the joint. So, if you are getting good color when fusing I imaging this current setting that you are running is to cold for when you add filler, which causes you to have to travel to slow. Which is turn is causing a lot of heat build up into the basemetal. This is just a guess though, i d actually have to watch you weld to really know the answer.

Poor gas coverage or to much heat input into the basemetal are generally the causes for a gray colored weld on stainless

For .063 wall SS tube for a starting point, I d set the dial on my machine some where between 50 and 75 amps. For filler rod i would use either a 1/16 or .050 308L. Which size filler rod that i use depends on the results that each joint design was giving me.

[customwelds]

I don't know if this could be a big factor, but I have heard of it making a little difference if you make sure you keep your filler rod in the sheilding gas. I don't know if it would make that big of a difference though.

[2gofaster]

Thanks Dan. I had been using 1/16 filler and tungsten with the machine set at 50 amps max. I went ahead and upped the amperage and the welds turned out looking much better. This project(turbo headers for a small block ford) is the first time I've welded stainless.