Clean the aluminum thoroughly
Remove oxide layer with a stainless steel brush
Degrease the surface with acetone or alcohol
Choose the correct welding process
Use TIG for thin, precise aluminum work
Use MIG for faster welding on thicker aluminum
Use AC current for TIG welding aluminum
Use 100% argon shielding gas
Set the machine for aluminum and the correct thickness
Use aluminum filler rod or wire matched to the base metal
Preheat thick aluminum if needed
Clamp the workpiece securely
Maintain a short arc length
Keep the torch angle steady
Move quickly to avoid overheating
Feed filler metal consistently
Watch for contamination and porosity
Let the weld cool naturally
Clean the weld after finishing
Inspect for cracks, lack of fusion, and defects