Etching with Potassium Persulfate

[burdt]

I have seen ammonium and sodium persulfates sold commercially as powdered etchants.  While searching for the aforementioned chemicals on ebay i ran into potassium persulfate.  the price was significantly lower when compared to the other two and after an exhaustive google investigation, i decided to purchase and experiment with it.  tonight it arrived and i carried out my preliminary experiment.  keep in mind i haven't ever etched before.

i took the nearest disposable piece of metal (an alligator clip) and i drew on one of the jaws with a 99 cent store permanent market.  i poured the hottest water i could muster from the tap into a plastic container and poured an undetermined amount of potassium persulfate (i measured it with a tiny shot glass) into the container.  with this horrendously unscientific setup i present my data:

the water turned an orange tint and the alligator clip turned brown.  after twenty minutes i removed the clip and rinsed it.  polishing it with some steel wool revealed that the crappy marker managed to spare what it was drawn upon, the rest of the clip lost all of its surface chrome and what was left of it turned the color of a new penny.  underneath the lost chrome is a dull grey.  i might post pictures if i manage to get my crappy camera to behave. 

the next step is a copper clad board and then an enclosure.  a pound of this stuff including delivery cost me about $13. 

[burdt]

thats the clip.  that's the best picture my horrendous camera allowed.  the marker covered up the bottom right of the clip's jaw.  it ended up marbled and partially eaten because the marker sucked.  you can see what parts the marker didn't cover up properly.  the rest is partially eaten away. 

[tranceracer]

I'd be interesting to see the results how it work on a Cu board. Do a simple boost or mini amp w/ sharpie.   

[burdt]

i'm thinking of making an orange squeezer.  i need to buy some copper boards first.  sadly, after perusing the board for persulfate etching of enclosures, it appears that it isn't possible.  i'll still try it just in case the potassium makes a difference but i doubt it.

[burdt]

it worked!  use the same proportion of potassium persulfate as you would use ammonium or sodium.  250 grams/liter. 
here's some pictures of it working. 




so yeah, there's yet another etching chemical.

this are my first circuit boards.  two guvnors, the tonepad layout.  i actually went to kmart and purchased an iron for this very purpose today.  my research included using two different types of paper for the transfer.  since this was my first, one of them smudged a tiny bit.  i used the glossy part underneath label paper, once you remove all the labels.  i had two to choose from, and the thinner of the two worked like a wonder.  didn't even have to hold it under the tap, it just peeled off.  i basically have an unlimited supply of this paper at work, so score one for me.