Date
Grit
Session Time
Grit Time
Cummulative Project Time
2010.01.14
Junk
1 .5 hrs
1.5 hrs
1.5 hrs
Here's a pic of the Pyrex glass I am using for the 8" telescope mirror. The jars are the 1-pound of #80 silicon carbide for hogging out the concavity. Each blank weighs about 6 pounds. I put an 1/8" chamfer along each edge to remove the sharpness and prevent cracks.
2010.01.28
#80
1.5 hrs
1.5 hrs
3.0 hrs
2010.02.04
#80
1.5 hrs
3.0 hrs
4.5 hrs
Sagitta is now 0.018".
