A flexible bubbler hose works OK for me.
The bubbles are not entirely uniform in density, but at least they are
small.
It is a black foam hose, with two rows of tiny holes cut in the outside
with something that must be like a pizza wheel. The hose looks identical
in make to the black soft foam isolation you get for refrigerant systems,
i expect is is from such a source only a very small diameter (maybe 1.5cm).
There's a lead wire inside to weigh it down -> remove.
I'd like to have a even more uniform bubbler since i still get streaks on
the PCB that etch faster, but i haven't found one yet.
BTW what a coincidence - my tank sprung a leak today! Luckily the plastic
safety container the tank sits in does it's job well. I drained all the
etchant into bottles and found it leaked in the same place again. The
etchant seeps through the gap between the edge of a panel and the bottom
plate which i must not have sealed properly. I had already put silicone
all the way around the outside of this joint to seal it up when it leaked
"back then", but i didn't do a terribly good job and such things tend to
come back and haunt you. So i carefully cut away the old silicone there
and re-did it properly. Will try tomorrow if it is OK now.
So, if you build a tank, do put silicone right on the edge of each panel
so this gap is sealed all the way. Check if it is sealed by looking from
the other side, i did not do that...
The aquarium people manage to hold together the whole tank by gluing only
at that very edge, i prefer to let one panel protrude so i can put i nice
bead on the outside of the tank. I glued the first tank outside and
inside, but it is tricky to get into a narrow tank so i didn't do that
with this one. It shouldn't be needed when the rest is done properly.
And do make sure the whole thing sits in a larger vessel that is reliable,
VERY reliable.
ST
On Tue, 11 Jul 2006 17:58:53 +0200, lcdpublishing
<
lcdpublishing@...> wrote:
> Hi Guys,
> I am working on a new etching tank for Ferric Chloride. I was using
> two bubble stones for aquariums, one clogged pretty quickly and the
> second one didn't last all that long.
> So, I figured I would take a sheet of PCB board and drill a bunch of
> holes in it as a baffle. The I would run an air hose through it and I
> would have lot's of tiny bubbles coming up. Nope, I got big bubbles
> out of a couple of the holes. I started out with .020" diameter
> holes, then tried .035, then .045" and finally .055" holes. Not
> working good at all.
> So, I am stumped now and am wondering what you guys are using to get
> better distribution of your air bubbles.
> Chris