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

----- Original Message -----
From: "dl5012" <dl5012@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, February 07, 2006 8:17 PM
Subject: [Homebrew_PCBs] Re: Dangerous Chemicals


> Hi,
>
> Glad you rang in on this topic...
>
> What is the proper way to dispose of used ferric chloride? Is there
> a way to rejuvinate it? Someone mentioned adding sulfuric acid, but
> everyone is imprecise about ratios. Is there a simple way to
> determine how much life is left in the etching solution? Is there
> an inexpensive way to precipitate the copper out of the solution and
> end up with just ferric chloride?

Adding H2O2 and a little HCl should convert any cuprous chloride in the
solution to cupric chloride, which is an etchant in its own right. Any
ferrous chloride would get converted back to the ferric form. I've tried it
and it seems to work.

>
> I'm hesitant to use some of the other recipes. I've used ferric
> chloride for many years and my main concern was not breathing the
> chlorine gas that gets released. Now, that I'm more environmentally
> aware, I want to know how to dispose of it properly. An old bottle
> I had from Radio Shack said to put it down the toilet. I'm sure
> that's not a good thing to do these days...

I just pour it down the bog!

Leon

---
[This E-mail has been scanned for viruses but it is your responsibility
to maintain up to date anti virus software on the device that you are
currently using to read this email. ]