On Mon, 29 Oct 2007 09:44:39 -0400, "Eisboch" wrote:

Those that are familiar with cleaning optics or glass know that an
indication that the surface is truly clean is that the water sheets, rather
than beads.

That was my experience wet sanding the bottom of my old racing
sailboat. When the water started to hang on the bottom in smooth
sheets, the surface was just about right.