Homebrew PCBs

I usually etch in a plastic food storage bin. If the etch is going slowly, I take the bath, board and all, and place it in the microwave for 60 to 120 seconds. Be sure to stay below boiling!! I use a meat thermometer to measure acid bath temp (it does corrode, but slowly) and stick with about 120F, 49C as the max temp. It does speed up quite a bit.

   SAFETY:
 In my microwave oven, the copper plate does not cause arcing but that may not apply to all microwave ovens. DO not let it boil, ore you will have hot acid all over the inside of your microwave! And it may through a few more bubbles as you take it out and the acid bath hits hot parts that weren't covered before.

  When ever I try brushing, I inevitably brush off the mask lines. That may mean my toner transfer technique is poor, but I just stick with non-contact etching to avoid problems.

Mike


--- In Homebrew_PCBs@yahoogroups.com, "txtom2" <unknown2@...> wrote:
>
> I just mixed up some Muriatic Acid and Hydrogen Peroxide (1:2) and tried etching a very small piece of PC board (cleaned and with no mask)to see how long it takes to etch thru (room temp about 75 degrees F). I saw a change in surface color in a couple of minutes, but no etch thru after 15 minutes. I changed the ratio to 2:2 to increase the acid content and after 15 minutes, no further apparent progress. 
> 
> Can someone please tell me what I'm doing wrong ? About how long should it take to etch ??
> 
> Thanks,  Tom
>