Thanks to Ann Sanicola, I have been learning to etch with salt water and batteries. I have done a lot of experiments, and thought others might like to see this
- resists (PNP, sharpie, stazon, oil paint, fingernail polish) anything to block the design from the etchant
- brine water (distilled water boiled with kosher salt until it will not absorb more salt)
- citric acid (find in the canning department of the grocery store)
- 2 9volt batteries
- alligator clips (2)
- plastic container
- copper wire
- tape, I have used painters tape here, packing tape is good.
I started today with a batch of salt water and saltwater with citric acid (1/2 teaspoon) that had been used once.
notice that the right has copper sediment and the right is just light blue with a few small pieces of copper sediment
Clean metal. Apply your resist (pnp etc)
Attach a copper wire to the back of the piece with your tape. Cover the entire back and sides with the tape so that your metal doesn't etch away
Use a bare copper sheet (called a sink) and attach to the side of the container. I just taped it, but a clamp would be great. Part of the copper (at least half) should be in the salt water solution.
Hang from a large gauge (I used 10g) copper wire so that the hanger is in contact with the large wire and the piece to be etched is hanging in the salt solution.
Clip the positive wire to the large wire and the positive side of the battery.
The negative wire to the copper sink and the negative side of the battery.
The sink will start to bubble. If it doesn't, check all clips. If it doesn't bubble it doesn't work!!!
I checked the depth of both. Needed more time. I shook the plain salt water one to make sure all the copper was not clinging to the piece I wanted to etch.
at 50 minutes I took both out of the water bath, used baking soda to clean and then scrubbed off the resist.
pnp with salt water and citric acid, very clean etch! depth good
pnp with salt water, look at the etching around the edge, not smooth. I know its hard to see!
these are the etched pieces. The one on the left is salt water and oil paint. The right side is sharpie with saltwater and citric acid. Hard to see but the citric side is slightly better etch, smoother and cleaner, not any deeper
For my purposes I will use citric acid, but will use a different power source, one that can plugged in. For teaching purposes I think 9volt battery will work.