One hundred and one TIG questions

"Brian" wrote in message > My big question is what makes the puddle jump up and bite my electrode? I I've had the same experience. Wonder what's happening or IF it's happening the way I think I see it...
Peter

| My third session resulted in a series of revelations. | | First and foremost among these is, I AM SUCH A DUNCE!!! | | I cobbled together an air cooled torch from a pile of parts I bought on | ebay. From among these pieces, and for no good reason, because I had | others, I used a top cap that had a broken end. I don't know what to | call it. But it's the black thing that to me, makes a tig torch look | like a pterodactyl. >>SNIP

first of all 2% T tungsten should be sufficent for all welding. They should be ground with the grain parallel to the tungsten not horizontal. MOST important the base metal should be CLEAN. Ground shiny clean, wiped down and excellent fit. Your gas should be around 20-30cfm. My 2% T electrodes usually last me months. Happy welding

Actually...no.
Gunner
The two highest achievements of the human mind are the twin concepts of "loyalty" and "duty." Whenever these twin concepts fall into disrepute -- get out of there fast! You may possibly save yourself, but it is too late to save that society. It is doomed. " Lazarus Long

gap damn near impossible to maintain.
Umm... no, I'm a newbie remember? The only thing I'm sure of is...its possible to survive an IRS audit. ;-) 1/16" maybe plus a little seems to work for me. -Mike

Carl, Fatumsch and all the others.
Thank you for your always valuable, and often humorous, insights.
If the weather's good today I'll give it another go. During a recent welding course I quickly got pretty good doing gas welding. Not ready to build airplanes yet but I FOUND THE GROOVE!
WIth TIG welding, in addition to the previous problems, I'm having trouble seeing under that cup. Even when I pay attention I have trouble seeing the end of the tungsten. Therefore, it's hard to know whether I've contacted the puddle widdit.
At this point I'd have to say it's at least one full notch more difficult than gas welding.
But being at heart a precision control freak I'm pretty sure it's going to supplant stick as my favorite process.
Thanks to everybody.
V

Bitternut,
It's precisely because of the "no health issues with lanthanated tungsten" that I just bought two boxes of these (1.5%) from Praxair. The 3/32" box (ten) was fifty two bucks and change!
However, both boxes (ProStar brand made in China just like Wal-Mart!) disclaim that "these tungstens contain small amounts of thorium, a radioactive substance..." or words to that effect.
I don't know if those words were left over after they recycled the label from their thoriated products or if even LANTHANATED tungstens contain thorium.
But for anybody who has an interest in this subject, a doubt STILL exists in my mind.
Vernon

Joke, right?
Hopefully another joke. There are no known health issues with grinding any tungstens other than Thoriated. If you don't grind the tungsten to a pencil point, you will get no arc control to speak of.
Very bad.
With a lift-arc start you have to touch and hold the tungsten to the metal for a full second before lifting. If you don't pause for that second you are achieving a scratch start, which is much more damaging to the tungsten.
Lift-arc does speed up the erosion of your tip.
The grind taper you want is that of a classic #2 pencil fresh from a pencil sharpener. All scratch lines need to be inline with the tungsten.
The tungsten should extend 3 times the tungsten diameter on a standard collet body, and up to 8 times the tungsten diameter on a gas lens collet body
On a gas lens anything more than 15 cfh will cause turbulence and is detrimental.
This is pure Argon tight?
Sounds more like aluminum.
OH MY GOD, you did not just say that!!. ALL METAL MUST BE GROUND CLEAN!!!
No rust, scale, paint, grease, wax or anything else.
Clean clean clean.
Got that?
Grind off anything that doesn't look like smooth round tungsten.
Dirty steel is useless to try and TIG, you will get tons of porosity.
No just pull out a grinder and clean your steel.

Well, finally, the King is back on his Throne!
Ernie,
I've been talking about (and for!) you while you've been gone. Damn, I'm such a kidder.
But seriously, welcome back and thank you for your response. In another post you'll see that the TOWERING problem turned out to be that I didn't realize that a frickin' broken cap might let some AIR in.
But I admit the process has been humbling. When my wife and I took a welding course together recently at Austin Community College I learned to run a pretty sexy gas bead. I thought TIG would be a snap.
Rem "Oh, that's "horse radish". Be careful. It's really hot!"
Well, at that time, being a veteran of several trips to Mexico I knew hot sauce! Hot sauce doesn't scare ME!!!
So I piled about a cubic yard of it on a cracker and threw it down the hatch!
Holy Moses! This is no stinkin' chile pepper!!!
And that's my take on TIG welding.
It's a whole 'nuther echelon of hot!
Thank you, Ernie. You're one of the crown jewels of this news group.
Vernon

Ebay
I recently bought 3 boxes of 3/32 thoriated, 1 box of 1/8" thoriated and 2 boxes of 3/32 1.5% lanthanated tungstens from a gent in Louisana
the total came to $15 plus $6 shipping
We were both terribley surprised. Me quite happily..him not so happy.
Gunner

A quick Google search of "lanthanated tungsten" turned up several on-line stores selling 10-packs of 3/32" 1% or 1.5% Lanthanated tungstens for around $15.00 + SH.
Example:

Now if I could just comlete this equation I would be content
Internet TIG Guru = steady paycheck

Vernon,
I'll jump on the reverse polarity bandwagon. I run a Miller SD180 at 160 amps on a 3/32 lanthanated electode and only have to regrind the tip if I dip it in the puddle when welding 3/16" aluminum plate or "L" . (Not too often now!) I can make 10 12" long passes with the same electrode, nice shiny ball on the end of it.
I do ball the electode using reverse polarity on a steel plate if I do regrind. I'm using 10CFM without a gas lens. Slightest breeze does kill things though. I have a 3 ton wall mount A/C unit in my garage and if I forget to turn it off I can tell within the first inch of weld as its contaminated. This is very easy to see on aluminum, not so easy on steel.
I always clean 1/2" either direction of the intended weld area to bright metal before I start welding. The contamination could be gunking up your electode as well.
I like to use MIG on steel as you get better build of the bead and burn right through any crap on it. All other metals I prefer TIG for the control and smaller welds.
Bart
Bart D. Hull snipped-for-privacy@inficad.com Tempe, Arizona
Check my Subaru Engine Conversion Check Tango II I'm building.
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Vern> My third session resulted in a series of revelations.

Bart,
Thanks for your informative reply.
I haven't had time to putz around with TIG in the last few days. But I hope to attempt a real weld the next time I do so.
I am aware of the need for cleanliness when welding. However, I figured the rust wouldn't matter since I was just playing with holding an arc.
Moreover, I did not know, until Ernie explained this, that the "lift start" feature of my welder REQUIRES you to hold contact between the electrode and plate for a full second before initiating an arc.
To do otherwise, (which is what I was doing) constitutes a scratch start, which erodes the tungsten. Add to that the fact I had a broken cap, a flow rate that was blanketing the planet (but not the weld), the rust, and my inexperience, all conspired to being pretty hard on the tungsten.
However, unless my welder is cross wired (doubtful) reverse polarity was not the culprit.
More later. Vernon