I can heatily not recommend letting locos cool without relieving pressure on the lubricator line. Oh, sure, steam oil does get drawn into the boiler to "lubricate" the boiler (a machinist did this to a loco I resurrected from his horrid touch), but that steam oil bubbles up into a foam that thoroughly inhibits steam generation and can displace water so the boiler is dry with only lots of steam oil foam. Took me a few attempts at firing the loco to realize why no steam was generating (well, first I had to remove the smoke generator that had burned through and put out the fire each time pressure rose a bit). Getting that foam out was not fun. It was tedious, repetitious, and took several hours of rinsing with alcohol before the foam was all gone. Then I had to let the boiler air out for a week, before refilling with clean distilled water. Needless to say, I am very careful to teach any who are curious to always open the lubricator to let pressure drop when cooling the loco down or when refueling. As long as pressure is maintained with the fire no worries about foam. I hate foam in the boiler, in case any of you wondered. Steaming & Sparking over Terror Trestle in Eugene, Oregon ~ Gary http://www.angelfire.com/or/trainguy http://community.webshots.com/user/raltzenthor
It would be nice to find an additive that could be put in the boiler water that would have a anti-corrosive effect relative to the copper, and that would be chemically compatible with all parts. Maybe someday someone will formulate such an additive. Cheers --- Bob
