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

If you can precisely pinpoint the location of the leak it is also possible to do a precise solder repair. But this requires some minute grinding at the leak site with something tiny like a dental bur, careful fluxing at the spot and very careful use of a small butane torch with a pinpoint flame. If you're not experienced with this probably best to leave it with its very slow leak, no harm done. You could also clean the spot as above and try a dab of epoxy like JB Weld or similar, pushing it into the joint where the leak is; let it cure 24 hrs before steaming again.