You could just flip the board half way through.
there are several plans/designs on the internet for vertical tanks.
I used
http://www.embeddedtronics.com/etchant.html as a starting
point. be generous with the aquarium sealer/adhesive. My first
attempt leaked just a little so I rebuilt it with about twice the
amount and it works good now. Be sure to buy the special knife for
cutting the plexiglass, it makes all the difference.
I sized it to hold 1 liter etchant so I could pour it into a
container at the end of the etch. Got an aquarium heater and air
pump. Drilled #69 holes in some 1/4" (6mm?) tubing for a bubbler.
The bubbler really works well in that etching is very uniform. with
AP and heater to 100F, it takes around 13 minutes. You will want to
build a lid for it because the bubbles cause some splashing.
Remember to cut some slots for the board holder(s) so it will sit
flat.
--- In
Homebrew_PCBs@yahoogroups.com, Stefan Trethan
<stefan_trethan@g...> wrote:
>
>
> Hi
>
>
> just want to inform you that the bottom side is etched MUCH faster
in a
> horizontal etch
> setup.
>
> HCl H2O2, from time to time moving the container around to agitate.
>
> at least half the time on the bottom side, the top just starts
> to clear at the edges and the bottom is already clear..
>
> i assume it is because the etched away stuff is heavy, and sinks
away from
> the bottom
> while it deposits on the top...
>
> so if you do single sided board do them face down,
>
> this is bad for doublesided, because of underetching....
>
> i start thinking a vertical setup might really have been a better
idea..
>
> any good ideas out there for a vertical tank pcb holder?
>
> ST