Welding Tips and Tricks

G'day all...

Have been trying to corner joint weld some thin (1mm) aluminium panels together to repair cracks on the folds.
I have found surprisingly enough that it takes about 100amps to get it going and around 80 to keep it going (foot pedaling). Plus a fairly sharp 3.2mm electrode works better than a balled up 1.6 or 2.4.

The big issue I have is with feeding the rod in. The filler rod (2.4 5356) melts really fast. Almost to the point of balling up before I can get it to joint itself.

Given I dont know what the makeup of the parent metal actually is other than aluminium, is there a better filler rod option, that will give me a split second more time to get the rod into where I want it, or do I just have to strive to get it in and out faster than I seem able to do as of right now?

I know practice makes "perfect" and I dont do much ally (mainly stainless which is so forgiving in this sense) but a little cheat would be nice if there is one.

Ta

Tony

You can go with 3.2mm 5356 rod. Another thing to look at is torch angle when maintaining the puddle. If you have it laid back too much (flatter more so than perpendicular) you could be melting the filler prematurely because of this. I know it happens to me sometimes when I'm not paying attention and go to do my first piece of tubing in a while

Torch angle more straight and don't put the filler into the main part of the arc stream. Instead, sneak/slide it in at the 'edge' of the puddle where it contacts the parent metal. Let the puddle pull it in what it needs. I know it's fashionable to stick tungsten way out these days but I have noticed it makes a lot of people lay the torch down too far. You might try choking up the tungsten closer to the cup as well.

Excellent tips thanks.
I'll try straightening up the angle and shortening up the stick out.
i am guilty of laying the torch over a fair way to see whats going on under the cup.

Cheers

Tony

On AC, the characteristics of the arc stream are exaggerated, so we kind of have to mentally scale up it's effects accordingly.

In welding school, arc stream characteristics are typically introduced early along with the basics of welding. After awhile, we may tend to take it for granted it in exchange for focusing on penetration, the puddle and filler timing, or as consistent torch angles etc become habitual. On AC TIG on aluminum, it definitely helps remembering it.

I get complacent with it occasionally. When I do you can tell. You will hear "pfooof," followed by me saying something like. . ."Paul. . .you dumb ass!"

Tony,

Every response I've read I agree with. Torch angle is a frequent issue, and I'm guilty of it myself on occasion, for the reason you gave... viewing the puddle.

Two techiniques I suggest trying, practice the rapid dab with the rod (sometimes your postion requires stick-out and torch angle), where you make very rapid "stabs" at the front of the puddle, but control how far you pull back so your rod stays shielded. The other is to feed the rod from behind the torch, into the back edge of the puddle. This requires keeping a little less current, because (it seems to me) to be slower, and doing a short back-step with the torch after each dab to keep the bead smooth. This technique is great for a root-pass in a fillet, as the back-feed fills the root depth, where a front'feed may chill the root and reduce penetration.

Two cents worth of crap I've tried...

Steve S

The term in question is "latent heat of fusion. While a metal remains solid, a relatively small amount of heat measured in BTU is needed to raise temperature. As it turns to a liquid, there is a pause while significant heat is absorbed and it becomes a liquid. After the puddle becomes liquid, temperature again rises quickly, in no time it is too hot,in thin material, if nothing happened to freeze it, it would keyhole. Dipping filler chills the puddle causing the back of it to freeze.
I recently journeyed to Mass. to Zapster's TIG clinic. The day was too short, it was my first time being in the same room with a skilled TIG welder. He believes it is more important to keep your filler out of the direct heat than in the gas cloud. He was not opposed to introducing filler from the side or even from behind. When Jody does it, notice how quick he is at dipping filler. His filler spends so little time on the way to the puddle, it hasn't time to take on much heat. It is important to use the heat in the puddle to melt, not the arc.

Thanks for the further responses.
I have not been able to get back to the aluminium stuff just yet as some delicate SS stuff needed to be done.

I must say that I love SS as much as I hate ally. Or perhaps SS just loves me.

Tony