Thanks all for the various comments. I don’t think I’ll be opting for any fancy coatings as I don’t know how good the mirror actually is nor how I’ll be able to fully exploit such a fast mirror without other aberrations being corrected.
Even if the figure isn’t that good, plain aluminium will do to let me play around with secondary optics with at least usable results.
Might be the worlds shortest dobsonian… ; – ))
I’ll keep you posted!