http://www.astro.caltech.edu/palomar/camtest.html

The 200-inch mirror at Palomar Observatory is being realuminized. It
was removed from the telescope yesterday and is being stripped in
preparation for going into the aluminization tank. They may almost be
done with the process now but it's hard to tell. If the new aluminum
coating isn't good (they'll know tomorrow after pumping the tank down
overnight) the process will be repeated, so stay tuned.

Mike Simmons