It really depend but more likely than not it is just sanded away but in level amounts:the whole lip in an even manner not just attacking the damaged area on its own. You have to remember a normal parking rash is actually only 1 or 2 mm deap. Of coarse if it is bad and chunks are missing and extremely deep then yes we will weld but that's where it gets a little tricky as you have to be sure to use similar grades of aluminium rods when welding as to what the lip/rim is made up from orrigonaly a:not to weaken the structure of the alloy using the wrong rods and b: so you can blend it in and repolish so the naked eye does not pic it up.
But the short answer to your question is it is normaly all rubbed down smooth the repolished to the finish of the oem style or the clients requirements.
Thanks for likes people. Keep them coming!