Got home last night and there they were all boxed up and waiting. Had a careful peek inside and all is good. Thanks Bintel once again.
Now I'm faced with a problem. I worry about the security of the diagonal hanging above the primary and my diagonal support has no flat surface (yet) to bond to. I want to add internal heating later so have the back surface exposed partially to the heater 'elements' inside to facilitate thermal transfer.
I am think of fixing some fine steel mesh cut from some instrumentation cabinets as a platform. This is thin panel steel full of small holes, about 1/8" diameter. Fix that as the flat diag support to the alum tube. Then bond the mirror at three points with aquarium silastic. The silastic will lock through a few of the holes thus securing it and the remaining holes will help expose the rear of the diag to the heater warmth and the metal is a good heat conductor as well.
I could make the mesh big enough to form small fingers to clasp the mirror gently at the sides, bottom etc. Use a bit of silastic between each finger and the glass edge. I still worry about it falling out although I know the fingers will intrude marginally into the light path. Am I being paranoid or over cautious?
Any other suggestions ?
Is there a better adhesive for glass ? ( I might do some glass/metal bonding tests to reassure my concerns ).
Techniques to ensure adhesion ? ( Alcohol cleaning eg )
Maybe I worry too much ....