Homebrew PCBs

I believe it has been said that 30 to 35% Hydrogen peroxide can be found at Beauty Parlor supply stores!
3% is too weak to bleach Hair!
73
Mike



________________________________
From: Alessio Sangalli <alesan@...>
To: Homebrew_PCBs@yahoogroups.com
Sent: Sunday, April 26, 2009 2:01:05 PM
Subject: Re: [Homebrew_PCBs] Re: What is the best etching solution;





jj_winkel wrote:

> Here in France it is easy and cheap enough to get "masonry" grade
> H202 (35% in weight or 130 in volume)used for wood bleaching and
> stains removal, and HCl (33%), so my recipe for 1 liter is : 750mL
> water + 50mL H2O2 + 200mL HCl in that order, etching time is about 8
> to 10 minutes,

In the US I haven't found 35% H2O2 so I use the 3% one. Result is that I
do not have to add water to the mix.

> But usually I only prepare 1/4 L (250 mL) enough for small boards
> everytime, as the solution cannot be kept and as it deteriorates
> rapidly it is best to throw it away.

Why do you say this. We discussed long that this solution is virtually
eternal...

bye
as




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