Very good work.
The boiler shell is too thin for a power boiler unless it was very low pressure. As diameter increases hoop stress increases.

I like your crosshead with large brass shoe. I have attached large brass and steel surfaces successfully with lead solder brazing.

I use these on the tug, they work just fine, a little more troublesome than flipping a switch, but definitely worth the nostalgic value. I have one of those with the with the large reflectors in perfect condition, paid a lot for it, they are sort of rare. Looks like a Wilcox Crittendon? Perko and So...

Fred, Thats a good drawing. There was a build log on this boiler somewhere on line. I don't know if I seen it or dreamed it, but I seem to recall a picture of one of these with short vertical tubes rolled in between the upper and lower drums on the same spacing as the generating tubes acting as down...

Lune valley with no welding. Although, I would arrange the tubes where they have a gradual rise throughout their length for better internal circulation, make them in a V shape. Also, make sure there are downcomers which could be piped in to the heads from top to bottom.

-Ron

Quote: " I again turn to forum enthusiasts with the question: how best to attach such thick tubes to a steam drum? Do you need welding for this? Is it possible to expand tubing in a steam drum to withstand 220-250 psi? Does anyone have such experience? '' Without welding, the tubes could be rolled e...

Quote ''porcupine steam boiler that I have never seen. But I cannot understand how steam is generated and circulated in such a steam boiler?'' Porcupine boilers have poor natural internal circulation and why they are not very popular. They do work as some have been built and used over the years. I w...

Here is an original George Whitney boiler that belongs to a friend of mine. The engine that went with this boiler was purchased by Webster out east of aluminum launch hull fame. The engine castings were copied and sold to a few people. A boiler design you may consider with larger tubing and limited ...

The question is rather vague, but the best tool I've found is a nylon cargo ratchet strap. Use a couple, tighten one and loosen the other. They will stretch a bit to allow another strip be installed without them all falling out. They will hold the strips while new bands are installed also.

-Ron

Dietrich, Very nice work. A suggestion. I restore very early steam cars as well as well as play with steamboats. Something I discovered recently for cleaning brass and bronze is a cheap simple formula. Take equal parts of salt and flour and mix them in a bowl, then pour in white vinegar until a crea...

Two boilers will work, they would need to be handled equally, same firing etc. If one were to be unfired no fire it would need to be isolated from the system as it would act as a condenser. Of course, if they share the same fire box that wouldn't be a problem. A rough general idea on boiler design a...