0,5mm to 1mm bubbles i have normally.
YES this is precious metric SI.
dunno how you live without it.
under the board may accumulate larger bubbles in tray etching.
with too much h2o2 i get bubbles, 2mm to 4mm in size.
yes, it gets warm, 60°C i think (you may convert that too ;-) ).
but only if i have too much h2o2. with just enough there is not much
heating, maybe 40°C.
tray etching.
my "permanent horizontal etching machine" is in work.
this will be a tupperware container where the etchant stays in all the
time.
the lid seals it off enough to prevent corrosion of your whole shop.
until now i used different trays and poured it back in the bottle each
time.
You should not seal it up tight with remaining H2O2 in.
i read the gas pressure could explode the bottle.
I have a horizontal board holder in planning.
i can send you a drawing, it is constructed in a special way
to allow using ALL the tupperware container area.
it also has only one plastic screw to adjust the with.
with a plastic ring wrench i plan to tighten this screw and at the same
time be able to slide the holding mechanism to the desired with.
for washing the board it is planned to use this same plastic wrench to
release
the PCB just a few mm over a water container.
this eliminates washing off the whole pcb holder each time (loosing
etchant).
the holder is not yet ready, you may want to wait for first results.
i can send you a drawing. the final version will be uploaded to the files
section.
i dislike the bubbler for making mist (which corrodes stuff).
the pcb holder i make will be affixed to the lid of the tupperware
container.
with slightly joggling the handle i hope to get occassional agitation.
(the board itself will act as a paddle). a motor may be used here but i see
no need.
ST
On Fri, 09 Jan 2004 02:24:18 -0000, dkesterline <desterline@...> wrote:
> The 3% wasn't my first chioce, but it was redily available and at the
> price, I wouldn't have felt bad if it didn't work. Cost wise it's about
> the same as 30% at $10 a quart.
>
> I don't ∗want∗ to throw it away, I was just comparing cost to Feric
> Chloride.
>
> After I etched for a while, it turned a darker shade of green, just like
> you said. The I added some more H2O2, (1/2 cup) it got very pale, I
> assumed it was from the excess water diluting it. But whith what you said
> about chlorine gas as a sign of too much H2O2, maybe it's not as bad as I
> thought.
>
> Please put a number to the bubble size, 10-20 thou? 50-100 thou? (I was
> getting some in the 50-100 thou range). It got warm, but not boiling
> (maybe 110 F)
>
> What kind of tank setup do you use?
>
> I'm thinking of getting an appropreate size tupperware canister and
> setting up a bubbler. Not so much for the oxygenation, but the agitation
> while etching.
>
> What do you have for a board holder?
>
> Thanks, you've been incredably helpfull.
> -Denny
>