I make my own PCBs and etch them in a homemade bubble tank.
The tank has failed after a couple of years largely due to the etchant slowly eating it's way through some of the materials (glues, pipes, tubes, sealants etc) that the tank was made out of.
There are a few youtube videos showing etching using rocking tanks to slosh the etchant around (as compared to stirring using bubbles) see this…
rocker tank 1
Has anyone got any experience of both methods and might be able to suggest which is best?
A bit of background might help. I make (on average) one board every 2-3 weeks. I used to use professional tanks, but was fed up of having to mix up 5 litres of liquid every time. (which would eventually need professional disposal). I ended up designing my own vertical bubble tank that would etch a post-card sized board using 250ml of etchant. I found this to be the perfect solution (for me) I would only have to mix up enough etchant for what I wanted, it would last for the couple of boards I might make that day, and then I could dispose of it properly myself and mix up a fresh batch next time needed to make a board.
It did a great job of making boards, The only problem with my design was making a tank that could survive the etchant, although most of the materials would survive weeks or months of exposure, after a while something was always getting eaten through and failing.
So rather than making another bubble tank, I though maybe a rocker tank, one advantage (to my thinking) being that a simple take-away container would be about the size I needed, and wouldn't require attempting to join pieces of Plexiglas.
The bubble tank made good boards, is a rocker tank as good?
Best Answer
Have you considered the magnetic stirrers used in a chem lab - they would probably agitate the fluid sufficiently then all you need is some type of bars / support to keep the panel above the stirrer... And you can use a glass container with should have a longer life...