What are the best TIG welding rods to use for repairing alloy wheels?
The highest strength Al-Mg alloy filler metal is always 5556 (triple 5 six is the common name), it was developed for the UK Navy, it's the best. It's both preferred and superior to 5356. 5556, available for both TIG and MIG, is the best as welded tensile strength provides good quality weld ability, toughness and ductility.
MasterWeld 5556 is available from this website in MIG and TIG welding wires. Bear in mind it is better to go up one size in diameter of filler wire when TIG welding to provide more volume of deposit and hence less dilution as well as to reduce porosity susceptibility.
Welding Tips and Techniques
Always use clean wire, clean weld preparation, good quality argon and eliminate all surrounding air movement.