Homebrew PCBs

Quite a few years ago, someone here gave a very good explanation of why silicone (the standard stuff) won't work with ferric chloride. Or any water in continuous contact with it. Essentially it works its way between the silicone and the glass or plastic.

Try aquarium sealant, it is made specifically to be in constant contact with water. Bathtub caulk is not.

Steve Greenfield