On Wed, 26 Oct 2011 20:54:22 -0700, wrote:

http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Michael Koblic,
Campbell River, BC

Was the original metal some type of casting? In that case, it could be
porosity in the original casting uncovered/opened up by the etching
process.

BTW: The sun dials you make are way cool. Do you sell them on a web
site?
Dave