Homebrew PCBs

The 3% wasn't my first chioce, but it was redily available and at the 
price, I wouldn't have felt bad if it didn't work. Cost wise it's 
about the same as 30% at $10 a quart.

I don't *want* to throw it away, I was just comparing cost to Feric 
Chloride. 

After I etched for a while, it turned a darker shade of green, just 
like you said. The I added some more H2O2, (1/2 cup) it got very 
pale, I assumed it was from the excess water diluting it. But whith 
what you said about chlorine gas as a sign of too much H2O2, maybe 
it's not as bad as I thought.

Please put a number to the bubble size, 10-20 thou? 50-100 thou? (I 
was getting some in the 50-100 thou range). It got warm, but not 
boiling (maybe 110 F)

What kind of tank setup do you use? 

I'm thinking of getting an appropreate size tupperware canister and 
setting up a bubbler. Not so much for the oxygenation, but the 
agitation while etching.

What do you have for a board holder? 

Thanks, you've been incredably helpfull.
-Denny


--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan 
<stefan_trethan@g...> wrote:
> On Thu, 08 Jan 2004 22:54:28 -0000, dkesterline <desterline@t...> 
wrote:
> 
> > Well, I finaly got around to buyng a jug of acid and trying this 
out.
> >
> > I bought a gallon of HCL (31.25%) from my local hardware store, 
$2.95 
> > (USD) Stopped by the Pharmacy and bought a quart of 3% H2O2 for 
$0.94.
> 
> you should not have bought the 3% stuff ;-)
> 
> >
> > Plastic container, about 1/4 cup acid, stuck in a piece of 
circuit board 
> > and started adding H2O2. At about 1/2 cup I could see some green 
tinge 
> > and the copper started changing. I poured in a litle more (about 
3/4 cup 
> > total) and the copper etched in about 8 minutes.
> >
> > About 1 cup total of etchant removed about 30 sq inches of copper 
> > (surplus scrap, but I think 1 oz) before it was quite dark and 
slowed 
> > considerably.
> >
> > I think the amount of water in medical grade would prevent it 
being used 
> > to recharge the etchant (to much dilution) but it certainly 
started it 
> > fine.
> 
> may well be (therefore my comment above)
> 
> >
> > Even if I had to throw it away instead of recharging it, this is 
still 
> > *much* cheaper than Feric Chloride. At these ratios a 94 cent 
quart of 
> > medical H2O2 and a cup of acid would replace a $12 quart of Feric 
> > Chloride.
> >
> do not, save the environment ;-)
> 
> > I did notice that it was much more unpleasant to be around (lots 
of nasty 
> > fumes) But I can work around that.
> 
> too much h2o2 if you got cloring gas.
> just bright green and TINY bubbles, not boiling like hell ;-)
> 
> >
> > Thanks
> > -Denny
> >
> 
> Nice it worked.
> 
> ST