Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Wow, Tommy, I just tackled a somewhat similar problem with my Doll marine. The drain cock was loose yet impossible to remove. I ended up soldering the fitting to the outside of the boiler. I know you're worried about loosening the nut inside the boiler, but as long as the fitting holds the thread, even loosely, you could solder it from the exterior and not lose the threaded nut inside. That would be preferable to using an epoxy or removing a boiler end I believe. Good luck. I'd like to see photos of the big Doll.