Homebrew PCBs

The problem with unagitated FeCl is that the sludge left is thick and 
inhibits further reaction.  It's the reason why the spray method works well.

It's my opinion that the sludge from FeCl is worse than several of the 
alternatives.  I've come to use Amonium PerChlorate in a tank with a 
submersible aquarium pump to keep things stirred up.

The trouble with using an air pump for agitation is that it tends to 
create some aerosols that you might not want to mess with.  I lost the 
head off of every nail in a storage shed that way :)

DJ Delorie wrote:
> I pre-heat the etchant (in it's bottle) in a few inches of hot water;
> it doesn't have to be *that* hot.  However, I don't just soak the
> board in etchant, I use a sponge to wipe the etchant across the board.
> I did a 3"x3" board today (er, 1 or 2 oz) in just a few minutes.  The
> mechanical action of the sponge really speeds up the process, but you
> need more than just toner - the sponge trick is a Pulsar trick that
> works with their green TRF, which seals and protects the toner.
>
>
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