[sausageroll]

Hi Everyone,

I have been tigging steel for a while now, and when I bought my current machine, I bought AC so I could one day start to do ally. Well I decided to give it a go, and I think I am on the right track but there is one thing I cant quite work out.

I am using a 1.6mm white tip tungsten, with a CK gas saver gas lens, and a CK flex loc torch (which I love). The machine is a UK built R-Tech, which has been amazing so far (atleast, I think it has been. Who knows how a more experienced welder would like it).

I have a bit of 3mm ally, which was clean and then i scrubbed the surface with a stainless angle grinder brush (new). The filler is 2.4mm. I can't remember my settings exactly, but I set the current to about 80 amps and floored it on the pedal (I decided I was not quite ready to do current control on the fly until I could run a decent bead with a constant current) I had my balance set about midway, and frequency in the middle.

My question is, how do I make a smaller diameter puddle? I seem to be making very wide puddles, about 8-9mm wide. I am holding the tip quite close to the material, but still it melts a large area. Am I using too much current? I know the frequency can effect the arc cone but in my experimentation, I did not see a vast change. I did try winding the current down but I find that it either does not puddle at all, or I get a very wide puddle. Is there perhaps a sweet spot were 1-2 amps can mean the difference between no puddle and a massive one?

I feel like for me to decide im ready to actually try and join two bits of metal together, I need to be able to run a bead about 1/4" wide down the plate, and so far, im not really able to do that. Is my filler too thick?

The picture below shows the narrowest bead I was able to make, at about 7mm wide. Also below, just for fun, is a photo I took of my practice plate with a thermal imaging camera. Kinda cool.






Any help would be greatly appreciated.


Pete.

[Otto Nobedder]

Pete,

Aluminum will always have a wider puddle than you're accustomed to with DC on steel. It's partly the nature of aluminum with it's rapid heat dissipation, and largely the nature of AC welding.

Narrowing your puddle is accomplished by adjusting your "balance" as far toward "negative" as the material will allow, but you will ALWAYS have a wider puddle.

Steve S

[TRACKRANGER]

Steve's exactly correct about the material characteristics of aluminum, but I might add that you could also try going to a smaller filler rod size if your job requires a smaller weld bead.
Trev

[rick9345]

Dial in more high frequency it can help and as Steve said DCEN as much as you can get away with till black flecs show and back it down some

[zank]

For 3 mm thick material, you should turn up your amps to about 125. At 80 amps, you probably had it floored for a while and soaked the sheet with heat before it puddled. That probably caused the puddle to get pretty wide and hard to control. With higher amps, you will heat a localized area quicker and it should narrow up the puddle. Then back off the pedal as needed as the part heats up.

[sausageroll]

Hi Everyone,

I did some more playing and I think ive got the hang of it.




A few things I have noticed, I was wondering if you had any input,

Its quite common for the arc to stall and start again... I am used to holding the electrode close to the puddle, maybe 1-2mm, when doing DC with steel. Should I hold the electrode further away for ally?

Also I know the electrode is not expected to stay sharp like DC, but shat should the electrode look like after a six inch fillet, sometimes the electrode has a little ball on it, sometimes its just kinda flat at the end. Its always dirty powdery blacky grey looking, and sometimes has a white powder on it (im still practising and screw up regularly)

Any clarification?

Pete.