For Wednesday’s Open House, we experimented with using simple, house-hold items to etch common, metallic objects. We found that candle wax, melted in a thin layer on the surface to be etched, worked as an excellent resist material. The firmness of the wax helped to keep the scratch lines straight, while the thickness of the paperclip made for a consistent stroke. We also tried acrylic paint as the resist, but it quickly dissolved under the cotton swab. We also tried the ink of a permanent “Sharpie” marker, but that was also easily dissolved under the cotton swab. We had other resist materials available to us, but these were the only ones that were “household” items.
Once the resist is set and the design is scraped out of the resist, the anode (negative terminal) of a 9v battery is attached to a bare metal area of the object, and the cathode (positive terminal) is attached to a cotton swab soaked with very salty (NaCl, common table salt) water. Within a few seconds, the electrolysis process creates a weak hydrochloric acid solution that eats away the steel of the object. After etching to the desired depth, the polarity of the connections can be reversed to oxidize the bare metal, as the now-anode cotton swab will produce oxygen molecules out of the electrolised water.
Here are some photos of our efforts.
Wax was at first a little difficult to scrape away consistently
I etched a little wine glass on my bottle opener. I believe this is nickle-plated zinc, hence the pinkish-brown color.
Matt made a negative etch of our hexagon on the bread box.
Brendan added a classic message to our bread box.
I managed a very clean etch of my monogram on my pocket knife. After etching to the desired depth, I then reversed the polarity of the setup to achieve the black color of the letters.
In addition to the electro-etching, we also had some fun toys to play with.
These Nintendo Wii-motes that Brendan is smashing apart will eventually become wands to be used with a Smart Board.
Brendan acquired a sick, Russian, night vision scope.
Brendan cautions one against extended exposure to the eye-piece. Apparently, the USSR did not feel the expense of leaded glass in front of a cathode ray tube was a necessary extravagance for their soldiers.
I found this circuit. I have no idea what it does. It looks to be audio related. Maybe an amp?
And then I just had fun taking photos of stuff.
Oscar Mike Golf! We have books!
We actually do occasionally receive post cards. Please! Send us more!
Okay, I showed up in a photo somewhere. Back behind the camera now.
We have one of the best views in the city.
Stop by next time when we bust out the big guns and… it’s a secret! Come by and find out!