I was a brain on the Dystopian Steampunk Costuming panel, and aside from my fondness for hammers ( I have 4, the TSA snared one I mistakenly had in carryon last year. I blame post-con brain).
This is the way to patina, etch, weather, wear metal.
Etching Brass, Copper, Bronze, Silver and Steel:
ALWAYS USE SAFETY GEAR: Mask. Gloves. Apron. Well ventilated work space. Handle chemicals with care, and dispose of them properly according to the bottle, to your city’s standards. There are some services that will handle spent etch. Think of the fish and the planet and the plumbing. Do not pour spent chemicals down the drain. DO NOT POUR CHEMICALS DOWN A DRAIN. EVER.
**Do not wear contacts while using etchants, as this can cause issues. Yes. It happened to my prof. Wear regular glasses, and your safety goggles. I accept NO responsibility for careless handling and not wearing safety gear. Don’t be that person.
Two relatively simple etching processes:
Ferric Chloride: Brass, bronze, steel and Copper
Ferric Nitrate: Sterling and Argentium Silver
A large glass dish with a cover: pyrex dish for the etching “tank”.
A rinse and neutralizing bowl.
Lots! of baking soda, as a neutralizer
Gloves: rubber if you can get them, latex housework gloves will do.
a respirator isn’t essential, but if you feel you need one, by all means.
PNP paper, staedler red ink pen, nail polish pen, nail polish to act as resists.
Packing tape, double sided tape and styrofoam chunks.
Burnisher ( can be found in most jewellery supply places for $10)
Prepare your metal. Clean it well. Soap, water. remove the oils from fingers and machining. You may want to do some filing to clean up sharp edges though this can be done afterward as well.
2. Apply the PNP resist ( my preferred method), using the instructions with blue PNP paper. ( Iron on “wool” setting. 45 sec. Burnish in one direction. Iron 45 sec, burnish in opposite direction.30 seconds. Burnish. dunk in cold water. peel off paper slowly.
( remember when doing PNP your image ie, letters, should be mirror image on printout).
2. Prep sides and back of metal. Cover the backside of metal with tape. Red staedler pen ( yes, it has to be red, it seems to work best) along edges so the etch does not make raggedy edges of your work.
3. apply the double sided tape, and stick styrofoam to the back of your work. This will “float” it in the etch.
4. Prepare your etch according to instructions on the bottle. Ferric Chloride is often sold ready to use, but Ferric nitrate comes in crystal form, and you add distilled water.
5. Float your metal face down, that is the side to be etched, in the etching liquid.
6. Go watch TV. Go check every 15 min, give the dish a gentle shake, check the depth of etching.
This is where time and patience and the randomness of the universe kick in. Sometimes the etchant isn’t good quality, sometimes its too hot, too cold, but usually with time, you can get a good deep etch on brass, bronze, copper.
Steel is trickier. It helps to agitate the solution more often and needs a much longer etching time. ( several hours to a day or two)
Silver also etches slow. Be patient.
Both ferric nitrate and chloride stain skin. Orange. Wear old clothes and gloves and apron. Really. Not kidding. They’re not overly “toxic” but you don’t really want to be getting this stuff all over bare skin either.
When the etch is deep enough for your liking, rinse, and scrub with baking soda to stop the etching process. PNP, and other resists can be removed with nail polish remover ( acetone).
finish your etched piece as you like. buffing, gentle sanding, filing, sawing, soldering, riveting. For brass, bronze, copper, and sterling silver, to prevent tarnish, I suggest Renaissance wax to seal the metal. Argentium silver won’t tarnish.
Patina chemicals can be applied, ( silver blackener, JAX patinas etc) and the etched portions raised, will stand out with gentle buffing with 1000grit polishing papers.
Gesswein USA/Canada: jewelery tools
Otto Frei: jewelery findings and tools
Rio Grande: metal, findings, etchant ( mordant), and resists.
Chemicals: I buy mine locally from an electronics shop, and chemical supply house. You’ll have to do some searching, most places don’t ship.
PNP blue paper: I order online ( ebay) from DP micro electronics in canada. You want PNP blue. Shiny on one side, matte on the other: photocopy the pattern in the clearest, darkest you can ( a general Office Depot copier will do the trick)
Other resists: nailpolish, asphaltum ( available via rio grande but I find it sticky smelly messy and hard to apply). Acetone to remove the resist works wonderfully.