Aluminum Gas Welding Using GTAW (Gas Tungsten Arc Welding)

Aluminum gas welding using the Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that is uses a tungsten electrode. GTAW can be used to weld many metals other than aluminum, including steel. TIG welding steel is easy, but welding aluminum is another cup of tea altogether. There are various factors that contribute to making aluminum hard to TIG weld.  

Here are the factors that make aluminum so much harder than steel to be TIG welded: 

Aluminum oxidizes a lot faster when left outside in the elements. This applies to boats, dock ladder, boat propeller etc. It creates problem when welding, which you should avoid by cleaning the aluminum before you TIG weld it.

Keep the settings right - the current setting should be A/C and the high frequency switch ought to be kept at continuous mode. If not, the arc will stutter. 

Since aluminum is a very good conductor, you will continuously have to control the amperage to keep the right amount of heat on the work piece. A foot pedal is a necessity here.

Your electrode should never be dirty, even with steel. But in the case of aluminum, it should be as clean as possible. Because aluminum is unforgiving with dirty electrodes, a dirty electrode will make your shop a very sooty place indeed.

The new types of TIG welding machines cannot suffer the use of pure tungsten, so be careful with them. With old types of machines pure tungsten may work, but avoid that with the new machines.

With steel, all you need is a 3/32" tungsten for almost all the common steel jobs, but that rule of thumb does not apply to aluminum. Aluminum is not as strong and needs just the right size of electrode. Keep the sizes 1/16", 3/32" and 1/8" tungsten handy because you will need them depending on the thickness of the aluminum you are welding. 

Aluminum gas welding is a different cup of tea, if only slightly. But that means a difference between a good job with repairing your boat and a boat that keeps on leaking. So be vigilant while TIG welding aluminum.