I just popped my fuel guage to check and noticed some rust on the tank in the cup below. Does anyone have a good strategy to take care of this? I was thinking of plugging the hole for the wire and fill it with vinegar overnight. Then wash it out and paint with rust protective paint. Any other suggestions?

 

Using vinegar over night might not do the trick depending on just how much rust there is . When I did an old tank , it took 2 days to fully rid the tank of rust . If your able , maybe some fine emery cloth or steel wool , and then painting might be quicker .