21AXP22 reliability?

[miniman82]

Bob nailed it. AXP's are vastly easier to repair than a 15G, though I've had success at welding both types of ultor flange material at home. The AXP appears to be made of ordinary spun mild steel, so all the rules for welding steels apply there. The 15G may be a little different metallurgically, I can say for sure that the metal 'flows' a lot better than mild steel does. It has a great affinity for itself, all you have to do is get the parts close to each other and apply the TIG torch and they zip together like they always wanted to be that way. Unlike aluminum where you have to keep dabbing filler into the puddle, or it forms a giant keyhole as the hot material expands away from itself.