Homebrew PCBs

Adi Linden wrote:
> 
> 
> Will aquarium supplies do for building a DIY etching tank? I am thinking
> air pump, heater, air hoese, etc. I am torn between building a small
> vertical etch tank versus buying a microwave for heating small quantities
> of etchant for sponging...
> 

Good question. I sometimes find the microwave/paintbrush approach does 
me fine for quick and dirty single sided PCBs. Not saying the etch 
quality is bad. I've messed around with bubble etchers over the years 
and found I could not get much better uniformity than the above method. 
Vertical immersion bubble benefits when you doing larger PCBs, > 100 x 
100mm (4"x4" for you Americans :) and you like to do something else 
while you wait.

As others have mentioned, you may not need to actually "build" your 
tank. There is bound to be something around that you can retrofit. You 
don't need air tight lid, just something to stop evaporation. Air hose 
can feed through a small hole somewhere at the top of the tank to allow 
use of the tank lid in a permanent setup arrangement.

Then of course there is the "float PCB on etchant surface" method, but 
in my experience this always left me with copper streaks and patterns 
that took much longer to etch. The result is poor uniformity, which 
causes some tracks to be over etched, especially the thin tacks.

Adam.