Mirror Making
I'm in the process of grinding my first mirror. When it's done, it'll replace the mirror that's in the aluminum truss tube scope now. Pictured here is the mirror in progress. It started as a 1.3 x 10" plate glass blank that I obtained from Newport Glass Works, Ltd. in June, 2000.

I'm attending a mirror making class at San Marcos College near San Diego. Bob May is the optical guru for the class and he oversees and supervises the work of the students.

Bob May pushin' glass
Bob shows how to push glass

Using a 4 inch diameter piece of steel (I think it was a gear of some sort) and some 80 grit, I hogged out some glass till I arrived at the approximate sagitta needed (the Parks mirror is an f/5). I had to remove glass to a depth of about 1/8" at the center. That took about 4 hours.

Then, Bob demonstrated how to make a tile and dental stone tool, shown at left. This tool, in various configurations, will be used to work the glass blank till it's finished.

The steps are:
- Rough grinding
- Fine grinding
- Polishing
- Figuring

That gizmo on the glass is a spherometer, a device for measuring the relative depth or height of a curved surface.