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Subject: Re: aquarium water pump for chemicals ?

From: "TonyB" <tbarros@...>
Date: 2008-10-18

Hi PBB DIYers. Thought I'd comment about bubble etchers using
aquarium pumps. I've been using the same aquarium pump for over
20yrs for my little bubble etcher. I use dry ferric chloride that I
mix up myself. I used to use a bubbler stone to help disperse the
bubbles. But, after about 15yrs, the stone I was using disintigrated.
I bought another, but, it seems it was made of a different material,
and disintigrated almost immediately! So, now I just use a T fitting
and attach multiple outputs off of it. Then, so the tubing will not
float, I set a clay brick on it. I sometimes add
more clay bricks to the bottom of the 5gal bucket that I use for my
bubble etcher. They help to displace the liquid and save on the FeCl.
When the etching gets slow, I add 1 cup of muratic acid (HCl) to the
bucket and let the bubbler work for 24hrs. The FeCl gets thicker, but
now has more CL in solution, so it can etch more Cu off the pcbs. I
haven't used the bubbler in quite some time since i built my spray
etcher. Pics of the spray etcher are in the photos area. I used to
buy one lb of dry FeCl for $1. A few years ago, the cheapest I could
find was $9ea + shipping. QUITE a change!! Hope all your etches turn
out clean. afn T


--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell <a_seychell@...>
wrote:
>
> lothar baier wrote:
> > tried that, didnt work, what workes is a pump like used in washers
or dishwashers, they are normally fairly resistant to chemicals
> >
> >
> What parts didn't survive in the pump that you tried ?
>
> I'd suspect dishwashers use stainless steel parts in contact with
> liquid. Alkaline dishwashing water wouldn't touch stainless steel. I'm
> pretty sure persulfates are ok with S.S, but forget ferric chloride.
>