Homebrew PCBs

On Thu, 08 Jan 2004 22:54:28 -0000, dkesterline <desterline@...> 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