The H2O2 I get from the drug store all say 3% on their labels. It works very well and quickly in my H2O2+HCl etchant. I've seen "food grade" H2O2 at 35% used in food processing and a number of alternative-health preparations (they actually drink the stuff--whoa!--though probably not without dilution). Google "food grade H2O2." You'll find lots of suppliers, including Amazon.
Todd, K7TFC
--- In Homebrew_PCBs@yahoogroups.com, Eddie Stassen <estassen@...> wrote:
>
> On Mon, Mar 11, 2013 at 11:38 AM, Leon Heller <leon355@...>wrote:
>
> > ∗∗
> >
> >
> > On 10/03/2013 21:20, Rick Sparber wrote:
> > > Leon,
> > >
> > > So is there a % concentration I should look for?
> >
> > 90% should be OK.
> >
>
> I don't think you want to be anywhere near 90% H2O2, unless you are making
> rocket fuel. I had a bottle on 60% once, and it is truly evil stuff,
> oxidises your skin instantaneously. I find the 40 vol stuff (12%) you can
> buy off the shelf is perfectly ok for etching purposes.
>
>
> [Non-text portions of this message have been removed]
>