Harry,
Thanks for the feedback (and Thanks from everyone else as well). This, of
course leads another question.
<snip>Could the bottom water glass bush in the backhead also service the
pressure gauge?
It could but you don't want it to. The gauge is best taken off a
high (dry) bush, or the fountain. <snip>
I am a bit confused by this. On one hand it makes sense to take the pressure
of the steam directly. But, aren't gauges required to be separated from the
steam through the use of a siphon? If the gauge needs to "read water" then
why not take the pressure from the "wet" part of the boiler. My reference
material is thin in this area, so I may be missing something. The Dee book
shows the pressure gauge bush located below the top of the firebox and I
would assume that this means below water level as well?
<snip> Do your preliminary sheet layout and rolling using shirt
cardboard.
It's much less expensive than copper. <snip>
The really cool thing is that the boiler is drawn as a 3D solid model and I
can use the software to "flatten" the conical course of the boiler. I can
accurately plot this onto paper and use it as a template to cut the copper.
I will probably do a mock-up in paper before making chips, just to be sure.
I know the CAD software is accurate, I'm more worried about my cutting,
shaping and soldering skills it's been awhile and there probably really
rusty (corroded?).
I like Vance's idea regarding a stepped boiler with the tapered course as a
"false wrapper". I think this is a more atheistic solution than a 2"
straight boiler shell. I plan on using this idea as plan B if the tapered
course is too difficult to form. It would also be a good option for those
that don't want to deal with forming the taper, if this design becomes
published.
I also like Art's suggestion about locating the formed backhead using pips
before brazing. It looks like the flat backplate filet soldered onto the
boiler shell is plenty strong and I would think preferable to forming from a
work standpoint. Is it bad practice to cut the plate oversized, solder, then
finish file the overlapping edge of the plate to match the contour of the
boiler shell? This is how I built silver soldered boxes for jewelry use. I
would assume that if the joint isn't filed into it should be full strength.
Ken
