Homebrew PCBs

You were correct. The bottle is labeled 32.something percent. Where
might I generally find 30% Hydrogen Peroxide? I wonder a bottle from
Radio Shack would be easier?

Mike



--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
> On Thu, 14 Jul 2005 17:15:59 +0200, Mike Phillips <mikep_95133@y...>  
> wrote:
> 
> > I should have some time today to get copper clad board from Halted.
> > Has anyone tried using copper pot and pan paste for cleaning bare
> > copper? I wonder how that would work over an abrasive pad?
> > I have a gallon of Muratic acid. Not sure of the strength, but I
> > bought it years ago from a wholesaler. It is typically used to help
> > deoxidize brass when soldering car radiators. I poured some on a
> > driveway stain one time. It makes kind of a yellow smoke. I thought I
> > remember the guy telling me it was pure Muratic. Can it be used for
> > etching?
> > Mike
> 
> 
> You could measure the strength of the acid but i'm pretty sure it will  
> work.
> It's surely not "pure" hydrochloric acid, those sales guys always
try to  
> fool you.
> When you remove the cap, do you see smoke? if you just see a tiny
hint of  
> smoke escaping it is around 32%, well at least in this climate.
> 
> To use it for etching you need to get some hydrogen peroxide (H2O2),  
> ideally around 30%. (The 3% medical stuff has so much water that you
can't  
> really regenerate your etchant, because it gets diluted too much,
but it  
> is ok for one-time use).
> Alternatively, you can use a bubbling system and air oxygen instead
of the  
> H2O2, but settle in for some wait.
> 
> Not sure about the pot paste. In the end you need a clean, grease-free  
> surface (real clean), how you get there shouldn't matter. Let us
know if  
> you try.
> 
> 
> ST