Welding Tips and Tricks

Hi
I'm new to welding Aluminum and have a small European (Air Liquide) AC/DC Tig welder with frequency and balance control.
I'm practicing butt welding aluminium pipe (1" dia 0.068" thick) with a 1.6 mm (0.062") thoreated tungsten, 1.6 mm filler rod, 60 amps, 100 hz and 60% balance but find that every now and then nothing seems right. I finally traced my problem to the earth clamp which is a simple spring loaded clamp but has one hell of a force compared to my old stick welder so should be giving a really good earth but isn't. I find all sorts of craters and pits and burning where the clamp grips the Aluminium that will be unacceptable on a finished job because it damaged the work.
Does anyone have any similar experience or ideas to solve this, the earth clamp works OK for stainless and mild steels?

The second problem I have is even though the rule book (at least the one I have) says use a filler rod the same size as the pipe my rod just balls up and disappears so I'm using a 3.2 mm (0.125") filler rod that's OK but I'd like to get a smaller neater bead if possible. Any ideas or suggestions anyone?

Thanks
Mike

For pipe I have a ground ("Earth") lead that is nothing more than about a meter of stripped 1-0 gauge weld lead stripped bare, which I wrap around the pipe a few times. All the little strands provide several thousand contact points to the pipe. Jody describes the same thing for a MIG ground to prevent stuttering starts. Alternatively, grind the spot you place your ground, so the current doesn't have to arc through the oxide layer to make contact.

As for your other problem, I'm going to take a stab in the dark, and suggest less stick-out, so you can keep your torch angle closer to perpendicular.

Your mileage may vary...

Steve

+ 1 to what Steve said.

Earth? That's pretty cool. I never heard that before. I speak American.

I thought there would be some discussion of removing aluminum from the earth or something.

I love aluminum.

Did you know that aluminum is the 4th most common element and it is the most common element in the Earths crust.

Though many scientists knew aluminum was there, the man guy who discovered a way to isolate aluminum worked for years trying to make it happen, but died only weeks before his lab was successful in 1825. Poor guy never got to hold a piece in his hand or reap the wealth associated with his discovery.

When aluminum was first available it was considered the most precious metal of all and was extremely valuable. The builders of the Washington Monument decided that it was so precious that they used it to put the point on the pinnacle of the obelisk. Now it is one of the most common metals. Its still good for scrappin though if you can accumulate enough.

OK sorry for the off topic talk.

The term "earth" goes back to Marconi and the first days of radio. If you've ever built a crystal set AM radio, one end of the tuner coil leads to the antenna, and the other to the earth, through a rod (or often an existing pipe) buried in the ground. The terms "earth" and "ground" are interchangeable in this context.

In a more modern context, "ground" is the common term for a common negative bus in a circuit, although in house wiring, the "ground" lead is tied to the earth through a ground rod, or more commonly these days a ground grid buried in the earth near the junction box.

Steve

OK, sorry for the very English use of the term earth instead of American ground but seeing as I'm a Britt I have an excuse.

Otto
Thanks for the tip about using a length of cable and the stick-out I'll try them.
Mike G

No sweat, Mike,

I speak English. Not specifically British English, nor American English.

I can easily use metric or imperial measures where it's appropriate.

I've never been caught "tossing off in the loo" , and I've probably "knocked someone up in the morning" in both the British and American meanings.



Steve

Have you lifted the bonnet to check your oil?

I was in GB during Christmas Holiday and the locals were always asking if if I had done any shopping. I told them "Not really, but I bought a pair of leather pants" Man, I got the funniest looks.