My mirror is very close to polished out now. less than an 1/8th of an inch to go and that is already about 90% there. Ten more laps around the barrel and I think it will be DONE!! 8o) Then 10 more laps with just a 10 pound weight and no pressure from me with slow strokes to smooth the surface. Though looking at it with the foucault tester tonight I could really see that the mirror is very smooth already. I will start figuring on Thursday. Perhaps sooner. With luck it will be ready for final finishing at the ATM workshop in Bellingham. 14" x 3/4" arg and first mirror too. I really must have been crazy. Thanks for all the help so far. Also a quick side note. When rough grinding a 18.5" please learn from my mistake. Don't get in a hurry and forget to give the mirror a good bevel. Small chip, not bad at all but a good warning and wake up call for me to slow down and not get carried away. For rough grinding the 18 I have settled on the STUPID DUMB INSANE counterweight that came out of the mirror cell on an 8" Meade Starfinder Dob. 7" diameter and cast iron. Works great and less filling. Had a purpose after all! Well Good night all. Jeez, who puts a cast iron weight in a mirror cell anyway!!!!???
Jack Day