[cj737]

Chip - Minnesota is correct in all his observations. But that is not to say you are still not making progress.

The picture of your tungsten clearly shows a fouled up tungsten! Grind it to a clean taper. It won't ball up on steel, thats an aluminum trait...

A flap disk should strip the scale off and leave you with bright shiny metal. Use the grinder at an angle to the surface, some light pressure, and push it along. Takes a few seconds, but it will come clean. I use 60 grit wheels preferably. The 80s tend to clog up with scale after too short a time.

For steel welding, you don't need to keep the rod under the gas shield. That's very true for stainless and titanium, not so for Er70-

One thing that might be happening with respect your heat, if you welded that piece at 160 amps, but still got a cold weld, you could be using too thick a filler rod. The rod added to the puddle "cools" it. So you could be using too small a cup for the lap joint (using a #5 on 1/2" plate for instance) that the HAZ is not wide enough to wet in the toes. I didn't notice the specs of the metal, cup, tungsten and rod, so this is general "speculation".

The angle at which you are holding your cup too could be contributing to hot top, cold bottom. Try to insure you're pointing the tungsten directly at the seam on a 45* angle. You might need to socialite the tip up and down a little as you go, but should be needed if the rod is the correct the diameter for the job. Lay the cup against the plate, maintain your angle, and slide along.

Don't fret, some of us mortals still produce welds like that even after years of success (of course those won't ever show up here)

Last bit of advice I might offer: If your machine has it, set the amps to a fixed number, ditch the foot pedal. Just dab and run. Focus on the mechanics of the torch/rod/weld until you get proficient. THEN introduce the pedal. This will allow you to limit your brain's activity list while learning.

[exnailpounder]

Hey Chips....damn the torpedos and keep welding. I'm glad you are pretty good natured about taking criticism. I try to build people up, not tear them down when they are seeking support. I wish we lived near each other so I could help you along. You WILL get to where you want to go and the most important aspect of that is that you are dug in and keep trying. You have my respect. It's always a head scratcher as to why people only put up their best welds for the world to see and you never see the warty ones. If you want to see an ugly weld, go see my thread on the cast iron repair I just did yesterday. I am capable of weld porn but it wasn't happening in this case. Repairs are usually different than nice shiny new metal sitting on a bench in perfect position. Don't use a grinding wheel unless you want gouges and a shitty finish on your metal. Flap discs are WAY better for not trashing your finish. You can't be shy about using one, put some ass behind it and get that scale off. Grinding takes some practice so you don't destroy your metal but it's easy. Hang in there.

[zank]

Are you on DC-? Sorry for the obvious question, but three things make me wonder. First is the balling of the tungsten. Second is the required 160 amps. And third is how there is a sootie looking deposit in a band away from the weld. It almost looks like there is some cleaning action and then some soot. Or my phone isn't let me see the picture in enough detail.

[Chips O'Toole]

I think I know what's happening with the current. I read that some welders have to reset when you move from trigger to pedal. I had the welder on the trigger setting last week, at lower current, and then I made a mistake and used the machine with the pedal. Some guy on a forum said he had the same problem, and the solution was to unplug the pedal and then plug it back in.

The balled tungsten is from me jamming the filler into it very close to the end of the bead. The black crap behind the ball is something I always seem to have.

I'll be back at it in a few days.

[MinnesotaDave]

As far as cleaning goes, even with mill scale your welds shouldn't look like that.

As an example (and I've said before that I need to go to tig hell for doing it) here's some no grinding prep tig over mill scale to "preserve the old metal look"

These are just hooks for the wall and were used to hang a cross at both hand and feet positions.

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image.jpeg (23.57 KiB) Viewed 1268 times

[AndersK]

...and that's a perfect example of where you should have cooked the weld to get that gray finnish Dave

Nice work though

[MinnesotaDave]

...and that's a perfect example of where you should have cooked the weld to get that gray finnish Dave

Nice work though

Haha!! Didn't think of that

[Oscar]

There is actually a lot wrong with the welds.

-The weld did not wet out at the toes.
-The weld contacts the metal at the toe at too steep of an angle creating a notch effect for a crack to propagate.
-Visually it was mostly put in too cold with too much fill creating an overly convex weld that created the problem above.
-Since the weld is cold, there is likely a lack of fusion at the root as well.

I had to look a few things up after reading that.

Too cold...I'm trying to figure out how that happened. I was getting a big puddle, and I kept dipping the filler to keep the puddle from getting too big and melting way into the upper bar. I would have expected "too cold" to mean a small shallow puddle.

I thought I was too hot, because the metal was heating up a lot, and not just close to the weld.

Remember, heat is not just about "setting the amps at the machine". Amperage is one thing, and voltage is the other variable. Not in the sense that you yourself set the voltage via knob/setting, but voltage manifests itself in the form of extra heat from too much torch angle and/or too much arc length. Both (too much arc length and/or torch angle) increase the size of the arc cone, by way of the machine increasing the voltage for you in order to maintain the electric arc lit. This dumps extra heat into the piece, but not like a water hose with a nice perfect cylindrical flow. It flares out a lot at the base metal, so the actual energy delivery (energy density) is less dense (watts/mm²) than if you have the optimum arc length/angle, because it's so spread out. So not all of your 160A are going where you want them go to/think they are going.

[zank]

Not to mention travel speed.

[Turbo]

Are you on DC-? Sorry for the obvious question, but three things make me wonder. First is the balling of the tungsten. Second is the required 160 amps. And third is how there is a sootie looking deposit in a band away from the weld. It almost looks like there is some cleaning action and then some soot. Or my phone isn't let me see the picture in enough detail.

Good question. Another obvious question: Are you using pure Argon?

[pgk]

Keep at it Chips, you'll get there. Looks a heck of a lot better than your first welds that you posted.


Pete

[Gene.243]

My hat is off to you Chips for posting your work.
I hope to get that good some day.
Mine still look like this.