Homebrew PCBs

Leon wrote:
> ----- Original Message ----- 
> From: "Dylan Smith" <dyls@...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Saturday, June 28, 2008 4:30 PM
> Subject: Re: [Homebrew_PCBs] Ferric Chloride - Alternatives
> 
> 
>> On Sat, 28 Jun 2008, Russell Shaw wrote:
>>> Well Geez, i've been etching with the same tank of FeCl for 2 years.
>> I've been using the same batch of FeCl for over a year (and many boards)
>> too, it does seem to last well.
>>
>> Someone told me that salt helps rejuvinate FeCl - not being a chemistry
>> geek I have no idea if this is right or not - is this true or is it BS?
> 
> I  doubt it. HCl and H2O2 works - I think that the H2O2 oxidises the ferrous 
> chloride and cuprous chloride to ferric and cupric chloride, and the HCl 
> provides additional Cl ions.

Every few weeks when i use it, i top it up with HCl. It's a bubble
etcher, so maybe the air has some kind of regeneration.