Interesting smoke stack position you chose there.
Hi Johnny,
Thank you, and that outlandish vertical bit, if you hadn't already guessed, is the steam dome tube. It was purposely made overly long for machining and forming purposes and it has now been cut down to less than half that height and is fixed in place. It looks so much more sensible now.
The silver soldering is going to be a challenge, due as always to the amount of heat needed. I have the torch firepower for the job but what I really need to have on hand is a capable assistant and there aren't any of those around here. Another concern will be handling. The final all-in weight will be more than I can easily lift without assistance so consideration will need to be given to lifting and turning gear (and/or an assistant.)
At this time my approach will be to solder things in sub-assemblies, first the firebox (with attached foundation ring, girder stays, and flues) an then the outer shell. Eventually those assemblies will be combined, along with the front flue sheet and back head, and given a final heat to finish. This approach has been successful on a couple of 5"ga boilers I've done, the difference will be that this one will take a great deal more heat. For that reason another consideration will be protective gear. For the boilers I've done in the last few years, including the 5"ga ones, I found I needed very little in the way of specialized protective gear; eye protection and leather gloves, but otherwise I wore typical workshop attire and a heavy apron. This one promises to be a different kettle of fish and I expect to need protection from exposure to prolonged intense heat. A boiler of this size at full soldering heat is akin to standing near the Sun, very uncomfortable.