Homebrew PCBs

I have not built something like this myself, but I suspect on a first
pass I would do what you did. Since that did not work I would start
thinking about it like a resistive series/parallel circuit and figure
out what kinds of resistances I would need to get an equal current
appearing out of the parallel branches.

After that I would try adjusting the sizes of the holes or channels
based on what kind of ratios I get from the resistor analogy.

I think I would keep the hole sizes the same, but vary the channel
widths to avoid any issues with capillary effects when going between
liquid and air.


--- In Homebrew_PCBs@yahoogroups.com, "lcdpublishing"
<lcdpublishing@...> wrote:
>
> Hi Guys,
> 
> I am working on a new etching tank for Ferric Chloride.  I was using 
> two bubble stones for aquariums, one clogged pretty quickly and the 
> second one didn't last all that long.
> 
> So, I figured I would take a sheet of PCB board and drill a bunch of 
> holes in it as a baffle.  The I would run an air hose through it and I 
> would have lot's of tiny bubbles coming up.  Nope, I got big bubbles 
> out of a couple of the holes.  I started out with .020" diameter 
> holes, then tried .035, then .045" and finally .055" holes. Not 
> working good at all.
> 
> So, I am stumped now and am wondering what you guys are using to get 
> better distribution of your air bubbles.
> 
> Chris
>