∗∗∗ Update ∗∗∗
I did some research for a formula using H202 (Hydrogen Peroxide) and
HCL (Hydrochloric Acid or Muriatic Acid)and found out that I was using
too weak of H2O2 at 3%. I had tried 3 times to etch a board using the
weaker H2O2 and had success twice but it took an extremely long time.
In deja.com, I looked for "etching recipe" and
found out there were different strengths of H2O2 available. After
trying several different outlets (drug stores, medical houses,beauty
salons) I found a place called Sally Beauty Supply that carries
several different strengths of peroxide (20%,30%, and 40%) in
different sized containers (quart half gallon, gallon.)
They also sell acetone in plastic jugs which will make it easier to
get into instead of the pry cap on the metal cans. Anyway, I came
home, mixed up 2 peroxide to 1 HCL and put my 6X4 board in. 10
minutes later, I had an etched board. Yipee. It was fun to watch the
board etch away. Halfway through the etching process, it started to
develop oxygen (I think). Air would develop on the bottom of the
board in the etching solution and bring the board to the surface. The
air would burp out from the edges of the board and it would sink
again. It did this for a 2 or 3 minutes. During the last minute of
etching, you could see the copper literally being melted off of the
board. I feel much better now knowing that I can etch boards in a
more timely manner. I was beginning to think there was something
wrong with me that I couldn't etch a board quickly using the HCL, H202
method like everyone else in this group.
--- In
Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@...> wrote:
>
> Please note that HCl has a low boiling point (somewhere just above
> 50°C). You do not want to heat this etchant too much.
>
> ST
>
> On Sat, Sep 6, 2008 at 7:31 PM, billshat44 <billshat44@...> wrote:
> > Update...It finished at 11:00. Barely any copper came off in the
> > first 30 minutes, but then the etching made noticeable progress. It
> > must be the cool temperature. By the way, the crock pot that I am
> > thinking about using is a crock pot that I use for cleaning model
> > airplane engines, not making a yankee pot roast.
> >
> > --- In Homebrew_PCBs@yahoogroups.com, "billshat44" <billshat44@>
wrote:
> >>
> >> I am currently etching a PCB with 2 parts peroxide to 1 part muriatic
> >> acid. It is cloudy and cool here and I am doing it outside to avoid
> >> the fumes. It seems like it is taking forever. I'm assuming it
is the
> >> temperature that is affecting the speed. Has anyone used a crockpot
> >> to warm the solution?
> >>
>