|
Welcome and don't be discouraged but I do recommend a smaller mirror fist for anyone contemplating making a 10 or 12" as you will learn certain techniques along the way that are invaluable for when contemplating a larger mirror. Start with a 6" or 8" or do both and then too you can use the tools that you used on each for the larger mirror in addition to a full size tool, particularly useful if you say want to do a 16" one day. The smaller tools can be used to correct zone errors.
It is very satisfying to create an optic from a piece of glass but it requires patience (lots of it) and attention to detail and persistence to get the accuracy and surface finish that you need. Along the way you will learn how to make optical test equipment as well as how to do the required tests and interpret the results which will come useful later for evaluating any mirror. Note 26mm is considered thin for a mirror of 12" size and given that it is plate glass rather than Pyrex it will have a larger coefficient of expansion. This means that even during figuring the mirror shape will fluctuate more than say a Pyrex mirror making figuring and testing more difficult.
Unfortunately cost of producing ones own mirror will likely be much higher than buying one of the mass produced ones but you will get exactly what you want. Note you don't have to get it aluminised until it is 100% to your liking as you can star test a non-aluminised mirror and also view the Moon easily at a good magnification as it is bright enough.
|