There are many ways to do intricate metalwork, but most of them involve expensive machinery or high-level training. One method, though, is accessible to all: chemical etching. This method is very similar to that used to etch hobbyist circuit boards: a mask is placed on the metal, and the non-masked area is dissolved by chemicals.
Brass is well suited to the process and produces attractive results. Shapiro Supply will sell you a .078″ thick, 8″ square piece for $11. See their listings on eBay (myworld.ebay.com/ssshapiro).
Design your mask and print it out on a laser printer using inkjet paper. Keep in mind that the mask covers the areas that do not get removed. The project shown here is a Victorian-style panel for a 20×2 LCD. You can find this design, and others by Andrew Lewis, in the gallery section of monkeysailor.co.uk.
Scrub the brass clean and then wipe with isopropyl alcohol. Place your print facedown on the brass and iron it for a minute or two, until the toner heats and sticks to the brass. Now soak the plate in a dish of water for 10 to 15 minutes, or until the paper is sufficiently soft that you can remove it. Remove the paper, then mask the back of the brass plate by covering it with gaffer’s tape (like duct tape, but it doesn’t leave so much residue).
Next, prepare a solution of ferric chloride (FeCl3). It’s available as a liquid solution from E-Clec-Tech (e-clec-tech.com) or as a solid you have to mix yourself from United Nuclear (unitednuclear.com).
Dip the plate into the ferric chloride and let it sit for 10 to 30 minutes. The time required depends on the temperature (warmer is faster) and the depth of etching required. When you’re satisfied with the etch, remove the plate and rinse it in water. Wipe clean with wire wool.
That’s it — a bit of ferric chloride and a laser printer are really all you need. This particular project requires some drilling and cutting to finish the LCD panel, but if you’re just doing something decorative, you’re done.
Copper can be used as easily as brass. Aluminum can also work, but be careful, as it gets very hot and gives off noxious fumes. Use a weaker solution.
It’s also possible to cut all the way through the metal. Suppose you’d like to make a cog. Print out 2 copies of the cog, and iron one to each side of the plate, lining them up. The ferric chloride will eat around the cog’s mask on both sides, leaving a hole where the 2 sides meet in the middle, and leaving the shape of the cog intact.
WARNING: Your ferric chloride should come with a Material Safety Data Sheet. Wear goggles, as it will blind you if it gets in your eyes. Also wear gloves and work in a well-ventilated area. The fumes are extremely noxious. Anything the ferric chloride touches will be permanently stained orange. More safety info is available at makezine.com/go/fecl3.
If you’re looking on eBay, you’ll notice you can get anhydrous ferric chloride quite cheap. Avoid this, as it gets extremely hot when mixed into a solution and must be added to the water very gradually. If you add water directly to the anhydrous crystals, it has the potential to flash into steam, spraying your face with boiling hot FeCl3. And you’d have to buy more ferric chloride, eliminating the cost savings.
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