First Attempt at an Aluminum Fillet Weld

[blasphemy000]

Only been able to weld aluminum since Monday and I haven't gotten much practice in. I got pretty decent at running straight beads on 1/8" plate so I figured I would give this a try.

I didn't back off the pedal enough at the end on the left side. My pedal is a little touchy as there's a dead-spot in the potentiometer which I plan to replace. I don't think this is too bad for my first attempt at this sort of joint.



Used these settings.

1/8" Aluminum Sheet. 90* Fillet.

Machine: Airco Heliwelder IV
Amps: 135A on the panel. Used pedal to regulate.
Polarity: AC
HF: Continuous
Pre-Flow: 1s (Not adjustable)
Post-Flow: 15s
Balance: My machine doesn't have a balance knob, so whatever it's hardwired for. Can't find any info on this.
Electrode: 3/32" 2% Lanthanated with a truncated taper.

[Rambozo]

Balance: My machine doesn't have a balance knob, so whatever it's hardwired for. Can't find any info on this.

Sinewave transformer machines are 50%, just like the input power. Same with frequency 60Hz in = 60Hz out.

Looking good. Take your pedal apart, you might find it's not a pot. A lot of older machines have novel ways of adjusting power, and you might be able to clean it up and fix it pretty easy. The old Miller pedals have a big straight wire wound resistor, with a wiper that rides on the windings. If it does use a pot, I bet it's a pretty nice one that you can clean out.

I found the pic I was looking for.

[undercut]

Only been able to weld aluminum since Monday and I haven't gotten much practice in. I got pretty decent at running straight beads on 1/8" plate so I figured I would give this a try.

I didn't back off the pedal enough at the end on the left side. My pedal is a little touchy as there's a dead-spot in the potentiometer which I plan to replace. I don't think this is too bad for my first attempt at this sort of joint.

Pretty nice! Dimes are quite uniform. Yeah, the end is a bit of a mess but there's an opportunity for some pedal cleaning and more practice.

Sinewave transformer machines are 50%, just like the input power. Same with frequency 60Hz in = 60Hz out.

Looking good. Take your pedal apart, you might find it's not a pot. A lot of older machines have novel ways of adjusting power, and you might be able to clean it up and fix it pretty easy. The old Miller pedals have a big straight wire wound resistor, with a wiper that rides on the windings. If it does use a pot, I bet it's a pretty nice one that you can clean out.

I found the pic I was looking for.

Man, the internals of that pedal are pretty beefy! Should be able to take quite a bit of abuse. Take a look inside of yours, Brad. I've got a feeling Rambozo is right on the money with his suggestion.

[blasphemy000]

Had the pedal apart yesterday and cleaned it, it's a 25K Sealed Pot, still has a spot about 2/3 of the way down where the ohms go up in the 100Ks. I figured the balance was 50/50, so no surprise there.
I can get the replacement pot online for $9.66 for a Honeywell Clarostat which I've heard are pretty good, so I'm just gonna go that route.
Thanks for the tips guys, and I'll keep up the practicing.

[MoparCar]

Good looking welds for the first shot! I bet that big 'ol 500 lb tank is pretty smooth! Glad it's working out for you. Nice job.

[blasphemy000]

Good looking welds for the first shot! I bet that big 'ol 500 lb tank is pretty smooth! Glad it's working out for you. Nice job.

Thanks man. I thought I did pretty good for my first attempt. I cut some more pieces and did a couple more fillet welds and a couple outside corner joints, and I'm getting better on the heat control at the end of the weld. No pictures yet though, when I become happy with my results I'll post more pictures.

I also found a way around the "dead-spot" in my pedal for now until I get the new potentiometer. The welder has a "Start Amps" switch and knob and when you enable this with the pedal, the pedal only controls the amps between the start amps and main amps. Even if you back completely off the pedal it will only go down to a minimum of what the "Start Amps" knob is set at, so it effectively gives me more resolution on the pedal for a given amp range.

As far as "The Tank" being smooth, yes, the DC+ arc in stick mode is silky smooth, the DC- arc in TIG mode is so smooth you can't even hear the arc, and the AC arc is also very smooth, stable, and not very loud. I'm absolutely loving this old machine, and despite its lack of a balance control, it will hold a truncated taper on a 2% Lanthanated electrode on AC, it's just awesome! I'm so happy that I found this old beast.

The only downside so far is the WP9-Sized 150A torch that came with it as it gets super hot, super fast. I plan on upgrading to a water-cooled CK200(250A) torch with 25' super-flex cables. I found the torch and the adapter kit to hook it up to my welder and I plan on building a cooling unit as my first project. All I need is the pump, I have a heat exchanger, some nice fans, and I'll be building the tank from aluminum. I think it will make a good first aluminum project.

[MoparCar]

Glad its working out for you! The water cooler will be a good project for the practice.