Hello Group,
I am a new subscriber to the group and have been following the thread for a
few days. I closed down my etching services about two years ago, providing
hobbyists and business small runs of single and double sided boards. I never
mixed my own chemicals. Always purchased etchant in bulk (Ferric Chloride).
The conversation on making your own etchant is very interesting. I wish that
I had found a group like this several years ago.
Grant's comments about muriatic acid made me recall that when I was in a
pinch and the order of etchant had not arrived, I had to come up with a way
to extend the life of what I was using. It is a good old trick to run down
to the local hardware store and get some muriatic acid to add to the
etchant. This would keep you going for awhile so that you did not have to
stop the production line and it did not give you undercutting problems as
some remedies might.
Best regards,
Mike Putnam
----- Original Message -----
From: "grantfair2001" <grant.fair@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, April 21, 2003 12:10 AM
Subject: [Homebrew_PCBs] Re: Cu + HCl -> CuCl2 : part 3
> Hi Adam - my chemist friend (who, incidentally, grew up near Bondi
> beach) advised me some time ago to try this recipe. I did not get past
> trying some copper in muriatic acide, and, expecting a quick reaction
> and getting none, giving up. (He had no idea about the time frame
> required, and no suggestions about what to do next). Here is his
> recipe, FWIW:
>
> "Dissolve 67 grams of copper in 100 gms muriatic acid solution (the
> 38% stuff). You could use an excess of copper to make sure all the HCl
> is consumed, but make sure you can remove the residual copper. Add 100
> gms muriatic acid and bubble the bejeezus out of it until it turns
> green. Add an additional 90 gms of muriatic acid solution and 606 gms
> of water and you should have about 900 mils of the recipe mentioned in
> the Rex Allers article."
>
> I think he got the 38% figure for the HCl from the article, since the
> muriatic acid available in hardware stores here is 20 Baume, about 30%.
>
> I don't know if that is helpful or not. He develops plastics for
> Dupont, so this is off the beaten track for him.
>
> Thanks for the idea for pumps for hydroponics - I will check it out
>
> Grant
>
> --- In Homebrew_PCBs@yahoogroups.com, adam Seychell
> <adam_seychell@y...> wrote:
> > I did another test. This time I simply put clean copper
> > metal in the 20% acid and bubbled lots of air through it. It
> > took just over 3 hours to completely dissolve the copper and
> > produce a deep green colored cupric chloride etching solution.
> >
> > makeup data:
> >
> > 40 ml of 26%wt HCl acid
> > 20 ml of water
> > 8.7 grams of copper.
> [snip]
> >
> > Adam
>
>
>
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