[pipe welder]

Hello I'm new to this forum. Im a stainless and carbon xray pipe welder. Also have to weld other things here and there. But my question pertains to aluminum. I had been welding pipe for 6 years the first time I ever welded aluminum and it was just a few tacks. Not enough to amount to anything. But the new place im working at involves a good bit of aluminum welding. Ive never got to watch anyone weld aluminum or got any instruction. So I did it for a few days on some ammonia plate repairs that got pressure tested to 300 psi. All of the welds were also small less than an inch long. Which passed the test no problem. The welds got ground off so looks didn matter. But today for the first time in my welding career I had to make some long aluminum welds where cosmetics applied. Some of them I just fused and some of them had to use wire. They came out looking great with a good shiny color but they were completely smooth. Similar to how a mig gun on carbon looks. Which I didn like because Most aluminum welds ive ever seen had that "stack of dimes look"...is something wrong for mine to come out smooth? And wat is the process for making that stack of dimes

[nickn372]

Somebody please correct me if I'm wrong but I don't believe you cannot fusion weld aluminum. Welding aluminum alters it make up enough that without proper filler it will not fuse. Again I believe this is right but I'm up for correction where necessary.

[rake]

Autogenous welding of aluminum is not recommended because of hot short cracking. Not that it can't be done but it usually
has a cracking problem. Stacking dimes is all about how you move the torch and dip the wire. Try to "jump forward" with the torch a little faster then dip to fill the puddle and repeat. Be a little more mechanical in your motion. like a clock works. Sort of a jump and stop motion. Your stack should be more pronounced. I worked with an old timer at the shipyard and his aluminum welds were smooth as a newborn's bottom. And he never had a problem passing QC.

[nickn372]

And there is your answer. I was close. Thanks rake.

[TwentyFourSeven]

I am no expert as I just started welding Aluminum my self a few weeks ago. From my very short experience having everything set right makes a night and day difference to how pretty your weld will look. The Tungsten must be sticking out the right distance, the gas flow seems extremely important. Also to small of a filler will melt to a flat puddle and be hard to keep up with. Aluminum gets to hot once you start to move an inch and requires backing of on the peddle a little or speeding up with your torch and filler. There is a very fine line between too hot and not hot enough (Especially thin stuff) Other than that just practice running beads with different fillers, electrodes and amps. Hope I was a little helpful.

[Arno]

Which I didn like because Most aluminum welds ive ever seen had that "stack of dimes look"...is something wrong for mine to come out smooth? And wat is the process for making that stack of dimes

Jody mentioned this in a few of his videos. The 'stack of dimes' look is often a cosmetic thing and practiced because a lot of people seem to like it. With practice you can get the same effect on many base materials.

Then I guess I'm odd as I like a smooth weld look on alu parts though

Bye, Arno.

[Bill Beauregard]

The advance the tungsten, heat the puddle, then dip filler. In that 1/100 th of a second the temperature of the puddle goes from very hot to freezing (for aluminum) in an instant. This usually forms a "dime". A lay wire technique will produce a smooth bead. I don't see smooth as unattractive.

[Braehill]

I too don't see a smooth bead as unattractive. As long as your bead width and tie ins are consistant, then I don't see this as a problem.

We have people out there trying to Mig like Tig and get the 'stack of dimes' look. In processes outside of Aluminum welding, I see this as a compromise to the weld quality by adding stress risers. Me I've spent my whole life trying to Tig like Mig. I rather have a smooth weld, but I always go against the grain, that's just my way and just an opinion.

Len

[rick9345]

stack of dimes''as per Braehill" stress riser and waste of material/time only when customer insists and extra charge.
Or welding as an art form and it is an individual's signature. Most artists are under paid.

[pipe welder]

Thanks for all your replies! Ive been laying the wire and rolling with it. Ill try dipping it in. I just thought something was wrong because ive rarely seen smooth alu welds. Made me think I was messing up

[pipe welder]

Also could I get sum input on tungsten stick out. Using 1/8 tungsten and 1/8 filler wire. Usually on about 260 amps on those ammonia plates...the stuff I talked about fusing was an 11 gauge tray and I was on about 190 with it

[MinnesotaDave]

Not more than the inside diameter of your cup size is what I was told for "rule of thumb."

So far it's seems to be a pretty fair gauge

(gas lens can push this rule a bit farther)

[MinnesotaDave]

Some "cool" gas pics

gaslenspic with smoke.jpg (15.76 KiB) Viewed 741 times

gaslens-1.jpg (30.08 KiB) Viewed 741 times

gaslens.jpg (26.93 KiB) Viewed 741 times

[WTFH]

Very cool pics!
Stickout of the tungsten is also dependent on the joint type. T joints especially acute angle T joints will tolerate more stickout because the gas is kinda trapped by the joint. On the other hand when welding an outside corner joint you should keep your stickout to a minimum because the joint traps no gas at all. I would say Dave's rule of thumb is pretty accurate. Gas lens or not, flow rate will factor in too. Bottom line you'll know when you have to much stickout especially with aluminum, it won't flow and kinda looks like wrinkled up paper and will be very dull gray.