On Mon, 09 Aug 2004 14:23:55 -0000, Phil <
phil1960us@...> wrote:
> that's not a bad idea at all for etching though I'd be very careful
> even with double bagging. Its a good, cheap way to do quick one-off
> etches. Even allows for aggitation though I'd be reluctant to handle
> a full bag.
>
> Still, I prefer the tank I made which has a bubbler and heater.
> Yeah, its more "stuff" and requires cleaning but I get very
> consistant, even etching and can do multiple boards at once. Pouring
> etchant back into the storage container is very precise. I'll stick
> with it.
>
Phil, the trick is to make the container in a way so that almost
no cleaning and no pouring back for storage is required.
(Though i doubt emptying and discarding the bags is less hassle than
cleaning
your container)
I have a glass tank for CuCl, which holds one liter and can do boards
approx. 30cmx20cm.
I keep the etchant in all the time (silicone adhesive seal for the lid),
if i need a board i lift the lid, clamp the board in the holder, put it
back in, etch.
(note: not touching any "wet" internal parts while doing that, the board
clamp is "remote controlled" through the lid and operated by the thumb of
the hand holding the lid while the other
hand positions the pcb)
When it is ready i lift it out by the handle, position it over the water
container, and push
the "remote control" for the clamp mechanism. the PCB is released and in
the water.
You see, not a drop of etchant is wasted because ONLY the PCB can carry
any etchant on it's surface
and is washed. the other parts never touch anything, and never get cleaned.
It is also sealed off enough so that closeby tools won't corrode.
The whole tank sits in a plastic container but there were no leaks so far.
The nice thing is you can clearly see both sides while in the etchant, no
need to pull it out
to see if it is completed. I have a hydrometer in there to see the density
(CuCl), and
also a electrolysis setup with carbon electrodes, but i didn't fire it up
yet 'cause i
think it isn't really useful. I could easily add a bubbler and heater
because the last 5cm
on both ends of the lid are separated and can be used to carry a hose, a
heater, or like it
is now carbon electrodes. I don't want a bubble because of the possible
fumes.
However, speeding it up is easy by adding mechanical agitation. A geared
motor
"sways" the holder from side to side (the silicone seal allows that) and
does
speed up the process a lot.
Best part: building was basically free, i had the glass and the lid/holder
is made
of old printer chassis. The slicone adhesive is the only cost.
I can only suggest to go on and build one, it is a big difference if you
have to prepare
your "bowl" and storage bottle, handle dangerous chemicals, or just open
the lid and put
it in there without getting your hands dirty.
ST