On Fri, 20 Mar 2015 11:03:06 -0700 Denny Esterline wrote: > It's been eight years since I etched boards, and when I did I held them > vertically with a bubbler for agitation, but I did not notice this proble= m > at the time. Yes, that would be a solution. But I make boards very irregularly and I'm not a fan of leaving the FeCl in the tub. Floating the board upside down is almost as fast as bubbles, but there is a lot less to clean up afterwards. John --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .