Welding Aluminum

I checked the archives, and most info has to do with gas welding with aluminum rod.

For maximum heat output in non-ferrous metals, an argon/helium mix will be beneficial. Helium does nothing more than transfer heat and it does that very well.

Mark also points out the importance of a liner dedicated to aluminum. A teflon liner is best for aluminum and will help aleviate feeding problems. A knurled drive roll will help prevent slippage. Keeping the gun cable as straight as possible is also a plus.

Of course, if feeding problems persist, U.S. Alloys can offer wire solutions. After all, we are known as 'Problem Solvers' to weldors.
Steve

We ship anywhere. Orders can be as small as 2#.

Check out our #320 stick electrode and our #328 torch alloy. It's on our site under the aluminum heading on the home page. Link

If you tried a teflon liner and knurled drive rolls, the only other option is a different wire. If you inquire about our #328MIG, be sure and tell them I recommended the 'stiff' wire to you. If you ever need help with one of our products, leave a number where I can reach you. If I can't get results for you, we'll take our product back.
Steve

This will give an ideal preheat temp for welding aluminum. Steve

To prevent burn thru on thin aluminum it can be beneficial to implement a heat sink. A piece of copper works best as it dissipates heat quite rapidly and in the event of a burn thru, the aluminum filler metal has no affinity to the copper.(Regarding the SMAW, GTAW and GMAW processes. Not necessarily true in some oxy-fuel applications involving certain filler metals.) A sheet of steel also works well.

In addition to utilizing a heat sink, there are substances available to also achieve that end and even prevent warpage on steel. That would be a refractory paste such as form-a-jig or the heat fence material available in caulking gun tubes. Very handy for hard to fit areas and for localizing heat. We recommend it for some cast iron applications as well.

Another inherent problem with aluminum welding is arc wander. This is prevelant when welding in enclosures where the magnetic field caused by the arc becomes so strong or when trying to join two sheets of aluminum as is often done in the floor of dump trailers and UPS trucks, for example. I have found it beneficial to use ordinary jumper cables to connect the sheets so both will ground sufficiently.
Steve

Thanks for all your help.

One thing, you will need to replace the wire feed liner inside of the cord that goes to the gun, as the steel wire will have contaminated the liner.

Thanks for the tip on the liner. Am I correct in thinking it would be a good idea to get a complete spare gun setup and swap guns when I swap between aluminum and steel? I'll have to check and see how spendy that idea is.

A good resource is "Performance Welding" by Richard Finch. I highly recommend picking up a copy.

If you plan on welding a lot of aluminum, I'd say go ahead a get another gun, I don't think that they're particularly expensive.