Homebrew PCBs

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