On Aug 28, 12:34*am, "W. eWatson" wrote:

Well, my old, third ed., of StarWare has several pages devoted to
commercial observatories. *My guess on the clam shell site mentioned
above is that a 7' shell is over $3K. That might cause me to think about
building my own obs. The 7' model comes pre-assembled and weights 600
pounds.

Are you fixated on a dome? Or would you consider a more practical (and
far less visually obvious) roll off roof? An aluminium dome is
lightest and least prone to overheating. Domes suffer from heat
retention and poor ventilation. Leading to potentially poor seeing.
They do however offer the best protection from cold winds and showers.
GRP/ Fibreglass is an option if you have the patience to produce a set
of gores from one mould. This requires careful work to achieve a
really smooth external finish. The popular hardboard and paint dome
can be rather short lived and is often heavy work to rotate. Marine
plywood seems to offer some advantages but requires care to seal the
joints.