ive been repairing my rims about twice now. the last one was the bad one, hit a kerb while turning! T_T so yeh, on my case, my guy actually grinds + sands the rims to make it smooth again! but i realise that after doing that the second time, wheels balance is abit off! after grinding+sanding, weights of the rims wont be the same, it wont be as perfect as factory standard! so yeh, if its a minor one , should be alright. but major damage, wouldnt recommend fixing it