Welding secrets for beginners and experts, everything you need to know about welding is covered, mig, tig, arc and gas welding, welding of all mnaterials including aluminium.
Even if you are experienced in welding steels, learning how to weld aluminum can still be quite a challenge. The oxide coating, lower melting point and high thermal conductivity, can lead to welding problems unless you know how to prepare for aluminium welding and setting up the equipment.
For welding aluminium, two main processes are generally used, mig (GMAW)or tig (GTAW)gas tungsten arc welding. While mig welding is used extensively in fabrication industries such as aluminium boat building, the most applicable for lighter gauge aluminium is tig welding both for strength and cosmetic appeal. Welded aluminium is used for such applications as aluminum bicycle frames, wheel chairs, fencing and balustrades and aerospace work, also commercial airline engine casings, seat frames, ductwork, and any-where else where lightness and strength is required.
Mig & Tig Filler materials
Tig welding filler material is available in short easily handled lengths where mig filler is on a wire feed spool, both come in various size diameters depending upon the aluminium to be welded. Keep filler material dry and free from oxidation and other contamination. If you use your mig welder for welding steels and aluminium you will need to replace the inner cable liner and welding tip each time you switch processes, aluminum liners are usually made of Teflon.
Aluminum work must be cleaner than steel workpieces to be welded effectively. The first step is to remove oils and greases from the workpiece by wiping the area with a solvent or washing it with a mild alkaline solution. The second step is to remove all oxides, which can be done with a stainless steel wire brush. Never use the same brush on aluminum and steel or it will become contaminated.
Not only do you need to clean before beginning to weld, but you also should remove the smut or soot between weld passes. This soot is fine particles of aluminum oxide and magnesium oxide. Proper welding techniques will minimize the amount of soot produced.
Usually, 100 percent argon gas is preferred for aluminum GTAW, but when working with thicker materials, such as 1/2 inch or greater, add helium in the range of 25 to 50 percent. Helium makes the arc hotter and provides for more penetration.
Torches and mig guns
If the welding application is light-duty fabrication requiring up to 150 amps, an air-cooled torch or hand piece may suffice. Higher-amperage jobs require a water-cooled torches and hand pieces. One feature to look for in a good torch is a flexible head, which offers maneuverability and reaches tight areas. Trying to access tight areas is a main drawback to using a mig set-up due to the size of the welding gun.
When you learn how to weld aluminium , you can reduce the number of errors you make by learning how to set up your welder using proper gasses, wire feeds, and electrodes and using correct preparation of your workpiece. Plus getting advice from tutorials and more experienced welders. In time, you will feel as confident welding aluminum as you do mig welding steel and oxyacetylene welding.