Clean both aluminium pieces thoroughly
Remove oxide layer with a stainless steel wire brush or abrasive pad
Degrease with acetone or an aluminium-safe solvent
Fit and clamp the parts securely
Choose the welding process: TIG, MIG, or spot welding
Use the correct filler rod or wire for the aluminium alloy
Use 100% argon shielding gas
Set the welder for aluminium and the correct thickness
Use AC for TIG welding aluminium
Use a push angle for MIG welding aluminium
Keep the torch and filler metal clean
Weld in short sections to control heat
Maintain proper travel speed to avoid burn-through
Allow the joint to cool between passes if needed
Inspect the weld for cracks, porosity, and incomplete fusion
Clean the finished weld if required
Wear proper welding PPE throughout the process