Homebrew PCBs

----- 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
Email: aqzf13@...
My low-cost Philips LPC210x ARM development system:
http://www.geocities.com/leon_heller/lpc2104.html