Homebrew_PCBs

Does anyone know if those flexible air bubble hoses used for fish tanks
are any good for ferric or CuCl etch tanks ?

see, http://store1.yimg.com/I/animalworldnetwork_1863_24150004

I know they have a lead metal insert that gives them ability to be
shaped, and provides the weight. If this lead is not covered in plastic
then it will not stand up to these etchants after a while. I've just
ordered some to try, as I'm having bad luck with other "air stones" sold
at aquarium stores.

I've tried garden "soaker" hose, but the consistency of air release is
very poor across its length. Its not designed for fish tanks.

I've also tried a series of 1mm holes in PVC tube, but the air bubbles
are too large causing very low back pressure. Again this gives very
non-uniform bubbling across its length. I found the air volume needed to
get good back pressure way too high (tested with water tank and a
compressor).

So I've come to conclusion you need lots of evenly distributed small
bubbles to get uniform agitation.

I use an hdpe tube (used for ice-makers or some such) and drilled the
smallest possible holes (.024 - about .6 mm). by trial and error I
found that if I space the holes closer together towards the sealed end
of the tube, I was able to get fairly uniform bubble distribution. I
heated up the tube first with a torch and bent it to shape - kind of a
"J" when the bottom is almost as wide as the tank. This took multiple
trials as overheating hdpe is not a good thing :). In the end, I got
something that is butt-ugly but works well enough. The bubbles aren't
small but I get very even etches.

--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell <a_seychell@y...>
wrote:

> Does anyone know if those flexible air bubble hoses used for fish tanks
> are any good for ferric or CuCl etch tanks ?
>
> see, http://store1.yimg.com/I/animalworldnetwork_1863_24150004
>
> I know they have a lead metal insert that gives them ability to be
> shaped, and provides the weight. If this lead is not covered in plastic
> then it will not stand up to these etchants after a while. I've just
> ordered some to try, as I'm having bad luck with other "air stones"

sold

> at aquarium stores.
>
> I've tried garden "soaker" hose, but the consistency of air release is
> very poor across its length. Its not designed for fish tanks.
>
> I've also tried a series of 1mm holes in PVC tube, but the air bubbles
> are too large causing very low back pressure. Again this gives very
> non-uniform bubbling across its length. I found the air volume

needed to

Adam Seychell wrote:

> Does anyone know if those flexible air bubble hoses used for fish tanks
> are any good for ferric or CuCl etch tanks ?
>
> see, http://store1.yimg.com/I/animalworldnetwork_1863_24150004
>
> I know they have a lead metal insert that gives them ability to be
> shaped, and provides the weight. If this lead is not covered in plastic
> then it will not stand up to these etchants after a while. I've just
> ordered some to try, as I'm having bad luck with other "air stones" sold
> at aquarium stores.
>
> I've tried garden "soaker" hose, but the consistency of air release is
> very poor across its length. Its not designed for fish tanks.
>
> I've also tried a series of 1mm holes in PVC tube, but the air bubbles
> are too large causing very low back pressure. Again this gives very
> non-uniform bubbling across its length. I found the air volume needed to
> get good back pressure way too high (tested with water tank and a
> compressor).
>
> So I've come to conclusion you need lots of evenly distributed small
> bubbles to get uniform agitation.

How about a block of porous carbon or charcoal? Glue a half-section
of pvc pipe along its length for the air-supply.

Another way is to drill 10mm holes in the pvc pipe and plug them
with porous carbon "corks".

On Wed, 14 Sep 2005 03:14:29 +0200, Adam Seychell
<a_seychell@...> wrote:

Stefan Trethan wrote:

> On Wed, 14 Sep 2005 03:14:29 +0200, Adam Seychell
> <a_seychell@...> wrote:
>
>
>>Does anyone know if those flexible air bubble hoses used for fish tanks
>>are any good for ferric or CuCl etch tanks ?
>>see, http://store1.yimg.com/I/animalworldnetwork_1863_24150004
>>I know they have a lead metal insert that gives them ability to be
>>shaped, and provides the weight. If this lead is not covered in plastic
>>then it will not stand up to these etchants after a while. I've just
>>ordered some to try, as I'm having bad luck with other "air stones" sold
>>at aquarium stores.
>>I've tried garden "soaker" hose, but the consistency of air release is
>>very poor across its length. Its not designed for fish tanks.
>>I've also tried a series of 1mm holes in PVC tube, but the air bubbles
>>are too large causing very low back pressure. Again this gives very
>>non-uniform bubbling across its length. I found the air volume needed to
>>get good back pressure way too high (tested with water tank and a
>>compressor).
>>So I've come to conclusion you need lots of evenly distributed small
>>bubbles to get uniform agitation.
>
>
>
> I have one very identical to the one in the picture, only black.
> I took the lead wire out, and then glued it to a plastic stick which i
> wedged into the tank with hot melt glue.
> The bubbling holes are in two rows on one side on my hose, and i pointed
> them up.
>
>
> It's still not entirely uniform, but it's OK now, and it would get even
> better with more pump power (have only 110 l/h on a 40cm hose).
> The smaller the bubbles, the more there are, and more importantly the more
> they will travel sideways in a random manner before reacing the top (large
> ones are more buoyant and go up the same path each time).
>
>
> Holds up well in CuCl.
>

Thanks for that. I'll try removing the lead wire or put a piece of
heatshrink tube over it.


I know what your saying about the more air delivery the better the
uniformity. I've had a few aquarium pumps over the years, and you really
need the "larger" type. I also ordered a piston type pump shown here;

http://avk.com.au/catalog/product_info.php?products_id=77&osCsid=b52294d9a298538f4bd203a7dbe86f28

manufacturer's site:
http://www.resun-china.com/web/Eng/ELECTROMAGNETICPUMPS.htm


At 20 L/minute (1200 L/hour) these piston pumps are cheap compared to
diaphragm types. But apparently noisy too, so forget using it on the
bedroom fish tank. I think for good bubble etching, air pumps should be

On Wed, 14 Sep 2005 11:33:33 +0200, Adam Seychell
<a_seychell@...> wrote:

> Thanks for that. I'll try removing the lead wire or put a piece of
> heatshrink tube over it.

Better take it out alltogether, if you have a leak it will eat the lead
and probably upset your hose with the remains.
Well, maybe, if you put glue in the ends etc.. But then, the wire
restricts the inner diameter a lot as it is, making it thicker i dunno.