There are small moisture spots on the steel support beams in my basement. I could be wrong but to me it seems like they originate from the inside of the beams. I tried priming and painting them with Rust-Oleum oil based primer and paint. After that didn’t work I tried again using the primer for rusty metal with another coat of paint. I don’t get water into my basement and I run a dehumidifier during the summer. Can you tell me what is causing them and what do I do? Thanks! I always learning something from your show!