Homebrew PCBs

Nice to hear you have good results too.
What i notice is that with a older etchant it takes longer and longer.
i do not know what is amiss but my solution hits the one hour mark now 
with
little enough peroxide not to make clor gas.

Was much faster in the past, i would like to have it that fast again.
Any ideas anyone?
I make a pcb about once a week so i would not like to discard it....

ST


On Fri, 13 Feb 2004 05:13:03 -0000, klmjr22 <keithlmartin@...> 
wrote:

> Just thought I would describe my experince using muratic acid and
> peroxide to etch a couple of boards. I used a plastic shoebox the semi
> white flexible kind poured in 1 cup 3% peroxide and 1/2 cup 32%
> muratic acid (swimming pool type) added slowly. the acid was about 40
> degrees as I store it outside. no fumes or bubbling was noticed during
> this time. The liquid was clear. Put in the board which was covered
> with riston dry resist and touched up with a sharpee. the exposed
> copper immediatly turned dark reddish brown and the solution turned
> emerald green in about a minute. Very pretty and quite clear. The
> board was 6" by 3 1/2" it was totally etched in less than 5 minutes. I
> used a gentle rocking motion. At no time did any noticable fumes come
> off the process. About 20 minutes later I started etching another
> board about the same size. When I started I noticed many bubbles had
> appeared on the bottom of the shoebox. the board etched much more
> slowly. I added about 1/2 cup peroxide and it sped right back up. When
> the second board was complete I neutralized the acid by slowly adding
> backing soda. when the fizzing stopped I diluted what was left and
> poured it down the drain. I realize it can be regenerated over and
> over but due to the small amount needed to etch the board and the fact
> I am very interrmittent in my etching needs making small amounts fresh
> seems like the thing to do. I believe what I ended up with was the
> cupric etching solution and if so it is MUCH faster starting with
> peroxide insted of bubbling for a week to get it started.
>