I'm still fooling with this and don't have much to show for my efforts. It is a challenge. I've burned up two transformers so far, so my next try is going to be with the battery charger and resistor.
I have been puzzling out which side the bubbler goes on too and have had the best luck with it placed on the negative side which is the side that has the junk piece of copper. I've had my sharpie ink flake off and also slide off.
I'm curious about the sludgy gunky stuff that coats the piece you're trying to etch. You get a bunch of it on the unetched piece of copper but the piece being etched gets a coating of it too. On one of my attempts I wiped it off and it removed my resist and quit etching the metal. Should I wipe it off or leave it on there until I'm done?
How many times can you use the water? And what do you do with the waste water? I've been trying to find out and have read a couple MSDS sheets on Copper Salts and they all say to dispose of it according to federal, state and local standards. I'm guessing I need to find my local toxic waste dump. So far I haven't found a feasible method to neutralize the waste water. I have read you can dilute it water to a safe parts per million but its an insane amount of water needed something like the amount needed to fill a swimming pool.
Any thoughts or tips will be appreciated
