Leakage while canning? Or simply rust from the bands?
I canned some roasted red pepper spread yesterday and there appeared to be a reddish leak. I noticed it on the lid after I turned the water off to allow the jars to sit for 5 minutes. After I took the jars out, I did hear the "pop" and today I tested the seals--they were fine and I so no reddish food remnants. But I did see some small rust spots on the bands (two of them, so not just the jar in question). Any ideas? I've not seen this before when canning, so I'm concerned. But the seals are really tight.
I guess you've figured it out, but I just wanted to say that I have had things leak out a tiny bit while canning before - the hot air that gets sucked out sometimes brings steamy jam/pickle-ness out with it. I've only had this problem when I take them out of the canning water right away instead of letting them sit for 5 minutes after the boiling is done in the warm water. The seals were fine, though, so it's not a big deal. My pickle book says it's normal!
The bands can start to rust quickly, often from the residual water on them after removing from the bath. As long as the seal is good you are fine!
I would remove the bands. Wash them and gently wash the outside of the jar and dry. The bands aren't needed for storage, they are just to hold the lid in place during processing. If it's a situation where you are shipping them or the pantry shelf gets a lot of rummaging about I'd put the rings back on for a little extra protection.