Good grinding progress
Today’s hour of mirror grinding has completely gotten rid of the low zone! Now I just need to grind down through that one tiny divot.
I noticed it seemed like my tool was pushing the water I sprayed out off the mirror. I used a blade to try to carve notches in between my hexagonal tiles, and afterwards I could feel the tool sliding more smoothly, allowing water to flow between the tool and the mirror. Channels are important!
Total grinding time: 4.9 hours