[aigel]

The blasting will put stress into the metal and they will deform. Ever sandblasted a thin metal sheet? This compressive stress buildup is used on purpose when shot-peening parts, i.e. connecting rods, but not good for your pans.

I would take the lids and go to WalMart or your local outfitter store and get a set of Lodge cast iron pans that fit your lids. These are cheap and cast iron is the best pan you will ever have if you use it properly.

G