I work at a museum that houses a large collection of historic fire trucks, dating from the early 20th century to the present. We’d like to preserve them for the future, and understand that draining the fuel is an important part of ensuring their longevity. Here’s the problem: Once we’ve drained or siphoned off the gas in the fuel tank, we need to let it air out to ensure that all of the gas evaporates. But that’s just not possible for us, considering all of the trucks are located inside, and we can’t have gas vapors floating all around the museum. Any suggestions on how to best handle this project?