Hi Tuggii,
I know what you exactly what you mean. I get in the mine dessert at times myself.
If I decide to build a long focal Newtonian I think I have to narrowed down to a couple of possibilities.
A 10 inch F10, or a 12 inch F8.
They would be rather long, but not enough to cause major problems. If it preformed well
?the pain would be wort the pleasure?.
Doing the math I was surprised the amount of glass to be removed from the mirror was less than I expected. Using the Sagitta formula:
S = 2F - sqrt((2F)^20 - (D/2)^2)
The Sagitta of a 10" mirror at F10 = 0.0625 = 1/16 inch = 1.5875mm
The Sagitta of a 12" mirror at F8 = 0.09375 = 3/32 inch = 2.3813mm
Focal length of 10" scope at F10 = 100 inches = 2,540.00mm
Focal length of 12" scope at F8 = 96 inches = 2,438.40mm
The 12 inch at F10 looks good but 120 inch length is getting rather long and cumbersome to deal with.
I am not sure how to deal with the diagonal mirror. But I think if I look at the focal length as a cone. Then determine at what point to change the direction 90 to the eyepiece. Then at that point just calculate the segment of the cone.
The ?rough? grinding of either mirror would not require a lot of labor time. The other thing is the final figuring and polishing should not pose a great problem.
When I calculate the arch of the circle, it appears long focal length mirrors are almost spherical than paraboloid.
I am beginning to think if one was careful and accurate, one could produce a very good mirror at a long focal length.
I have a chemical formula for depositing a silver coating to a material (namely glass).
The only problem is the glass is required to be cleaned with H2SO4 . However, there are other methods just as good. But if absolutely require then I will use the sulphuric acid.
I also have an old vacuum pump and would be willing to try depositing a thin layer of aluminum.
Yes, truss looks good, it at least would make it a bit portable. I could also use a two section tube with a sleeve between the sections
I almost have myself convinced to attempt one of these.
Yes, got Vesta the other night as well as some dimmer Messier objects.
Vesta is just below and to right of M104.

"We live in a changing universe, and few things are changing faster than our conception of it."
- Timothy Ferris