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

I think the flared ends on that boiler speaks to the split cylinder issue that we sometimes see with Jensens. Which is to say that the press is mightier than the elastic modulus of the material, such that ramming a slightly oversize endcap into the end of the slightly undersized cylinder C-bore, stresses the walls of the cylinder. Later, under thermodynamic load that stress becomes telling .... or so I think?!?!

Not too sure I'd have ever let a boiler looking like that out of the shop. In fact, I'm sure that I would not have let it out, but I suppose that is just my years in QA talking.