Why? Is this a critical thing with the digital machines? I am speaking of welding steel, not aluminum. I have a Miller Gold Star machine and it could absolutely care less if you dipped the electrode into the puddle or not. What happens if you have a contaminated electrode? Again, i am speaking of welding steel.
The main problem with dipping (contact with the electrode to the puddle) is first possible tungsten contamination of the weld which creates a small internal hard spot flaw as the tungsten tip off the electrode does not melt in and blend with the weld. This applies to steel and other alloys as well. The second part of electrode contamination is that the arc coming from the electrode will not be as precise and focused and may be harder to control leading to undercut on the edges of the weld or other problems. Losing 1/2" of tungsten is too extreme. Maybe for aluminum welding but even then all I ever do is grind off the contamination and re-sharpen the tungsten. Good to go.
So when you have the goo now and again like all of us tig welders,do you just keep on welding like nothing happened? Wouldn't you consider stopping and grinding the tungsten.You must agree that you loose a great part of your arc control and precision in d/c mode! Now what just keep on welding as if it doesn't matter what the weld looks like.No the part won't fall apart.Yes you could keep on welding no one said you couldn't.Mite be ok welding on a plow,how about an aircraft fuselage,NHRA chassis,your own hot rod.I have seen some poor welds on more than one street rod.No inspector is going to let a compromised weld pass.The statement about falling apart or throw it away are just words.It is always nice to give a finished product back to your customer and take pride in your work.Sell a steak with the sizzle.None of this post is directed at you as a welder just a response about the falling apart and throwing it away. A non welder could interpret that as "lets get er done" its ok.You must admit in your career as an experienced welder you have seen some welds that you say to yourself WTF were they trying to do? I will fix this for you. M2¢ T
The thinking and theory and what is taught is that Goo imbedded into the tugsten and fused with it. That's why they say to break it off. That shit ain't cheap and I don't break it off. I try to grind it off and maybe grind 1/8x off the whole end and point. It never gets it all but its usually enough to get going on work that will be covered. It its going to show and I want it as perfect as I can get it, ill break it off if I dip it. Just for a comparison, take a brand new tungsten, a gooed but ground, gooed and not ground, gooed broke off and ground.... Take those and weld some beads. You will notice a difference between all 4. The new one and broken then ground will be pretty close to tge same. Make sure you grind them on a dedicated tungsten wheels. Here's the interesting part, un less you break it off you are contaminating your wheel. See ...
I agree with Blue One that breaking off is much more common with aluminum, where the AC actually drags more contaminants up and embeds them in the surface of the tungsten behind the point. It's actually pretty obvious when to break off or just regrind. I've seen literally tens of thousands of student TIG samples over the years, and it is absolutely apparent exactly where the tungsten was dipped, and whether or not it was reground before the bead was finished... (I will note that these are raw beads, purposely not cleaned after welding) Bottom line is, welding with a dirty tungsten requires too much heat input to form a satisfactory puddle, which in turn creates a wider HAZ than necessary, increasing the likelihood of stress failure due to embrittlement. This is MUCH more important on 4130 (chrome-moly) than mild steel, but the same rules apply regardless.
Yes, it'll wander and then if you are very clever you can 'tap' the tip and it'll clean and keep strokin. If bad wander you just got to do something about it. When you are layin inside a chassis operating the box with your knee and have a block of wood under your head supportin the shield you don't take time to crawl out and redress the tip. All my chassis welds are certified, all my chassis have serial numbers and i am honest enough to admit to welding with less than pristine tip. I also worry about any welder that places a high order of importance on appearance, the weld is first and if it be pretty then it'll be pretty. It is my experience that welders who make things pretty do so often at the expense of the weld. I have fixed a shitload of pretty welds that tear esp on the rear axle bracketry, when brakes are hammered at the end of a pass it'll rip the brackets off a housing. If interested you can see some of my welding in my photo gallery, you'll find funny cars, promods, topsportsmen etc a couple of which are world champion and the the worlds fastest nitrocoupe...you needn't worry about any of those welds failing.
First scratch-start TIG attempts: These were done with no pedal, amps set between 70-85 i don't remember which one was which and it what order. Gas was set a 25 gph which i think may be too high but that's what the instructor wanted so.............. Feel free to comment, criticize, augment etc. Don't hold back----any helpful critisizm is appreciated and welcomed.
Clean off all mill scale tig must be squeaky clean.Just run some puddles without filler rod and practice freezing the puddle and then move on again freeze again til you get the puddle under control.Don't worry about filler rod till you can read the puddle.Then attempt to join cupons with your puddle control and filler rod.Ask lots of questions.How thick was your metal what filler rod size and what amps and what welder?all is important to give a solid resoponce. Tig
WAY too much heat for the thickness of material. Bleed through should be no higher or wider than the material. Bead size at FAR right of pic #2 is getting close to the correct shape/size. You can get the weld done with far less heat if you open up the root gap. Typical "rule of thumb" for steel is 1/2 metal thickness. Can't really tell what thickness you are welding, but it looks like about 14ga?
Yep, clean the scale off first. With that scale there you need way too much heat to break it down and melt it, when melting it that contaminates your weld. Too much heat makes for a wide puddle.
So, you're saying i need to cut down on amperage? i think it was 11 gauge and when i first started i put it on 71 amps but one of the instructors said i need more amps, so we put it up to 85ish. (?)
Here's the problem with dirty metal and tig welding. (tig likes clean clean clean metal) sometimes you can't have what you want - if its not then .... You will need more heat to burn thru the crap, junk, oxidation, and scale and god knows what else is on it. It's difficult to get a pure ground and the arc can't get to pure steel and there for ground. When you turn up the heat to burn that crap off some of it vaporizes and contaminates the gas covered area - its no longer inert. Some of it gets into the puddle and contaminates the weld. Some of it gets stuck on and bonded to the electrode and when that happens you need even more heat . It's a viscous spiral. You'd be surprised at what a little bit if dirt (especially paint) will do to your really nice bead
11 ga is about .090 give or take. 85 amps is about right, so I'm gonna say you are too far away with the tungsten, or it's not prepped correctly (dirty, or not ground correctly). When you regrind, rotate the tungsten under a light and look at the reflection. If you see "facets" like a diamond, the arc will wander. the tungsten should throw the same reflection the whole way around as you rotate it.
The Jalopy Journal
