Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

----- Original Message -----
From: "lcdpublishing" <lcdpublishing@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, June 27, 2005 5:36 PM
Subject: [Homebrew_PCBs] Re: air pumps


> Forgive me, I am sure this has already been discussed but...
>
> I don't know if air is required or not so keep that in mind.
>
>>From the little I have read so far, you need agitation, not actually
> air. Air is just a way of moving the liquid around for the
> agitation. It also seems that most of the rigs for this are vertical
> to accomodate the rising air.
>
> Would this work...
>
> A shallow, flat tank, sitting horizontal. Across the center is a
> pivot point and at one end a very small, slow spinning gear motor
> with a cam on it. The cam rubs against the bottom causing the tank
> to rock back and forth. This would cause the liguid to move back
> and forth in a wave motion.
>
> Adding a couple of standoffs to the circuit board before putting it
> in the solution could be used to keep the board off the bottom of
> the tank.
>
> If nothing else, it might be relaxing to watch it rock back and
> forth :-)

I do the same thing, manually. There was design for something like your
suggested tank in the ARRL Handbook a few years ago. The etchant was kept
hot with a heat lamp over the tank.

Leon

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