Finally Finished grinding J

(Day 5, total of 30 hrs so far)

When we last left off, I had just unstuck mirror B from the tool, and the result was a bunch of scratches and a “bruise” fracture. Yesterday was not a great day, but I did learn never ever hit your glass with a hammer!

To help avoid the sticktion problem I was advised to cut 1 mm deep 2mm wide channels across the surface of my tool. To do this I used a dremel with a fiber cut off blade in it and LOTS of water. This went real well, and I cleaned the cuts up with a knife sharpening stone. Unfortunately no pictures were made of the tool.

Now having channels in my tool, it was time to get back to pushing glass. Dumped some 25 micron on the tool and went back to work. After 3 hours of this I had removed the scratches, then I did an hour at 15 micron and an hour at 9 micron. Then the sticktion monster got me again!

Back to 25 micron to get rid of a few real minor scratches from the tip of the air nozzle I used to release the stuck tool. mirror. Another lesson learned, cover the tip of the air nozzle with a rubber hose!!!!!!

The newly created scratches ground out quickly at 25 micron, then I did 30 minutes at 15 micron and 30 minutes at 9 micron, and to temp fate, I did 4 wets at “Toothpaste” level.

Toothpaste level, what is that you may ask. Well I had received counsel from the ATM elders that I should finish grinding down to 5 micron, unfortunately I didn’t have any 5 micron grit. Dominic, from the ATM list, said whitening toothpaste was the equivalent of 5 micron. I had a tube of Colgate with Advanced whitening formula on the bathroom counter, so I figure what the hey.

After 1 wet of toothpaste, I compared the toothpaste level mirror with the 9 micron level mirror. The red-out test showed a significant improvement of the toothpaste mirror. So I continued on, doing a total of 4 wets per mirror at toothpaste level.

Remember those “bruise” fractures I mentioned? Well there still there. Fortunately they don’t show on the surface of the mirror, and they are rather small, about one half mm at the largest. Here are some pictures of the damage, which I am going to ignore! Time will tell if this is a mistake or not.