I am about to make the Boiler for my 9F Loco, The plan size shows a tube dia. of four and five eighths but I can get a copper tube of 4 and a half inches.
Is there a problen if I use the smaller dia.?
I would make up the dia. with cladding and insulation mtl.
I have a rolling chassi and have completed the Tender. The whole model now awaits the boiler and firebox. Have yet to make the cab.
Clive