RE: ATM Grinding Grit

[Bob Prabowo <BOB@bahana.co.id>]

Hi guys,

        >I used almost 6 pounds of grit but it was cheap enough at $2.35
a       >pound

Do you all really use that much a grit? 
When I hogged my 13" I only used less than 1 pound of grit #60 (I don't
remember if the #60 grit came in 1 lb or 2 lbs package, so it's possible
that I used mush less than 1 pound)  after the depth was about 3 mm or
so (maybe it's more than that, but I don't remember), I switch to #80.

I only used a small amount of abbrasives and water for each wet (about a
half of teaspoon of abbrasives and one spray of water with pistol grip
sprayer) but a lot of sweat and energy.
The tool I used to hog the mirror was 5.6" in diameter and covered with
coins. I think hogging is more effective (read: works faster) than
chordal stroke, and IMO one must try to hog his or her mirror at least
once. It's a good exercise and will help you sleep better.


Bob P. Sumitro
Jakarta, Indonesia

visit my still-under-construction astronomy and telescope making page:
http://www.geocities.com/CapeCanaveral/Hall/2670/