Homebrew PCBs

On Wed, 24 Dec 2003 12:40:09 -0000, Leon Heller <leon_heller@...> 
wrote:

>
> ----- Original Message ----- From: "Stefan Trethan" 
> <stefan_trethan@...>
> To: <homebrew_pcbs@yahoogroups.com>
> Sent: Wednesday, December 24, 2003 12:26 PM
> Subject: [Homebrew_PCBs] horiziontal / vertical etching, how to make a
> sealing lid
>
>
>> Hi!
>>
>> I'm thinking about my etch tank.
>> Even if i make a vertical tank how can i make a airtight lid?
>> I want to keep the etchant in and prevent too much corrosion.
>>
>> The lid shoud keep all gases in.
>> it should have a overpressure valve (because of decomposing H2O2, that 
>> is
>> no problem).
>>
>> Additionally it should prevent spattering.
>> (when the tiny bubbles (from the h2o2) burst there is etchant splattered
>> out of the tank.)
>
> Some industrial cleaning tanks have plastic beads floating on the top of 
> the
> liquid. That might be all you need - they will prevent splattering and 
> cut
> down evaporation. You can just lower the PCB through the beads.
>
> Leon
> --
> Leon Heller, G1HSM

Thank you for the information but i'm not very fond of the idea.
It isn't really preventing evaporation totally (i forgot a tray beside some 
drills and had to
brush and oil them afterwards - don't like that again.)
And i think there wil always be beads sticking to the pcb/holder and so 
on...
I would rather like to have this thing closed well.
(i now store the etchant in a glass bottle with a pinhole in the lid for 
releasing pressure.
it stands close to iron parts and no rust at all for years)

ST