Quote:

are you joking or what??
Should be made out of aluminum?




Many small planes are made of chromoly. I think mild steel would be very uncommon due to the weight. Hey, they used to be made out of wood !!!

The welds in roundy-round cars are usually migged because they're mild steel and a mig weld is fine in that application. The weld itself is big and fat because they lower the heat and weld in a circular pattern. The lower heat gives less distortion and maintains the metal integrity while the circular pattern provides the penetration. You will see tig welds but they'll often be used to attach a thick bracket where the amperage required for adequate mig penetration on the bracket would just blow holes in the cage tubing.