My Uncle gave me a small Pancake air compressor for my garage and to use around my house. Not knowing the last time or how often the tank was drainind, I drained it out the other day and a Rust Color like slude/Water came out. Not a whole lot, but it the color that worries me. Is it normal to see a rust color brown come out of the tank or do I have internal problems? Do you think it is safe to continue to use this air compressor? It is not that old, can be more then 5 years old if not less. Thanks for the help, don't need this thing blowing up down the road!!!