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Subject: Re: updates on cupric chloride etching. part 2

From: "grantfair2001" <grant.fair@...>
Date: 2003-04-11

Hi Adam - well this is quite timely, since the source I hoped could
provide methyl orange, Cole Parmer (LabCo in Canada) does not sell
chemicals and to date, other local companies I have found won't sell
chemicals to individuals.

Thanks, I will read the website information provided with interest.

I did find some copper - bright shiny wire end pieces about 12" long,
maybe 14 ga; 5 pounds at $1.50 pound. I think the scrapper was
surprised I wanted to buy it, not sell it. Quite a few characters
hanging about the place, too, so it was a minor adventure to visit.

I have a friend who is a plastics development chemist with Dupont, but
when I asked him about cupric chloride and related issues, he said I
needed to find a "wet chemist"; it was too far from his experience. It
seems like you have found someone who is truly expert, and helpful to
boot - a great find.

Keep us posted. The copper will go into my tank tomorrow to get me
started, I hope, so by next week I may have a progress report.

Grant

--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell
<adam_seychell@y...> wrote:
> Grant,
>
> There is some interesting reading inside the technical section on
> http://www.oxfordvue.com/
>
> http://www.oxfordvue.com/TechInfo/copper_and_acid_normal.html
> they suggest the correct procedure for acid titrations. It so
> happens that you DO NOT use an indicator because its more
> accurate to rely on the initiation of tubidity change rather than
> color change on indicator. The CuCl2 + NaOH will form insoluble
> Cu(OH)2 once all the free HCl acid is consumed. Well that news
> makes it easier and cheaper for us.