Anyone know of a repair method for aluminum rims?

My wife dropped by a tire shop today with one of my rims/tire and the tech told her the rim itself was leaking due to some corrosion. He replaced the valve stem and chipped off the oxide (free!) and it's apparently leakless now (checked in a tub at the shop). I ask because I forsee more difficulties in the future with the (ZX gold cross) wheels and would like to know what I'll be up against when it comes time to refresh them.

Most likely such leakage is in the bead area, a good cleaning to bare metal before tire install should elimanate any problems there. Any other leaks would likely be caused by cracks, and in that case I would consider the wheel scrap.

There's no welding that can be done in that circumstance?

I believe you can weld the wheels but for the cost of replacing factory z wheels I wouldn't I know it isn't cheap. But usually if you have those cracks there are visual problems or balance problems which are worse. Most of the air leakage issue with corrosion is easily fixed with a wire brush and the wheel alone on a balancer . I fhte build up is excessive just a screw driver and hammer will remove the main stuff then the wire brush. But all the build up you will encounter will be on the inside bead of the wheel , usually where the mounters have used lube to get the tire mounted or where water has entered the tire and settled there. You should be fine after a good cleaning I am sure with the future wheels as long as you don't see any visual damage. Good Luck