rust comes off by the lb man, dont get em, they'll disintegrate within a year or 2...
Good stuff, thanks for the links.Go for it.
Here's some links for you:
RossTraining.com Blog
How to Clean Weight Plates | eHow.com
Clean Weight Plates | LIVESTRONG.COM
If they're good, name-brand plates like York or Weider and just have a light coating of rust, they're probably okay as far as structural integrity.
But if they're some off-brand and have layers of surface rust, big seams of rust, etc., coating falling off and revealing rust, etc. you should probably skip 'em altogether. 'Cause their structural integrity might be compromised. You don't need chunks of rusty metal exploding off a plate when you drop the bar.