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Hello,
Thanks again Rod, do you seal the Plaster of Paris(PoP)/concrete mix? What sort of ratio are you using? I assume more concrete than PoP and you shouldn't need a sealant?
Thanks
Steve
Ps. I was referring to Texerau’s method of making individual pitch squares, just seemed an easy way to change the lap if I wanted to change the polishing across any of the zones.
Yes, the sharpie test works well, but that's all I have done and the wet mirror test for F/l of course. No Ronchi/Foucault testing till I get the first polish on and built a test stand etc. Just focusing on strokes and any uneven progress in smoothing between the zones, which so far there hasn't been.
One reason for the F9 was bugger all difference in spherical to paraboloid and only 1.41mm of glass to remove. Also to see if the refraction spikes are reduced nicely for what is essentially a star splitter/cluster/planet sort of project.
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