[loneronin]

... some other test results.

I followed some ads like use a real felt and not toilet paper on the pad, put a piece of stainless steel plate under the felt, etch small areas and try shorter etching time with higher voltage.

1 - 9 - see post #1 of this thread

10 - output: DC, 5V, 2,40amp; distilled water and salt; pole + to the blade, pole - to the pad (felt); etching time: 30 min; no stencil/mask/pad damage

11 - output: DC, 5V, 2,40amp; distilled water and salt; pole + to the blade, pole - to the pad (felt); etching time: 10 min; no stencil/mask/pad damage

12 - output: DC, 5V, 2,40amp; distilled water and salt; pole + to the blade, pole - to the pad (felt); etching time: 5 min; no stencil/mask/pad damage

13 - output: DC, 20V, 3,25amp; sulfuric acid (from an old car battery); pole + to the blade, pole - to the pad (felt); etching time: 5 min; no stencil/mask/pad damage

14 - output: DC, 20V, 3,25amp; sulfuric acid (from an old car battery); pole + to the blade, pole - to the pad (felt); etching time: 3/4 sec on - 5 sec off 10 times; no stencil/mask/pad damage

15 - output: DC, 20V, 3,25amp; distilled water and salt; pole + to the blade, pole - to the pad (felt); etching time: 3/4 sec on - 5 sec off for 5 min; stencil/mask/pad damaged