Electroforming Solution RecipEs
Warning: Electroforming, when all necessary safety procedures are followed, is a safe, stable process. Because the electrolytic solution is primarily composed of copper sulfate and sulfuric acid, proper gloves and eye-wear is a must, as is proper ventilation. And because electroforming utilizes electrical current, a full knowledge of safe electrical workplace practices is necessary. Please carefully read the safety precautions for all the chemical materials you purchase, as well as all safety precautions for the rectifier. Also, research the risks associated with all component chemicals before you proceed. Cornell University's toxicity report is a good place to start for copper sulfate, and Iowa State University's Material Safety Data Sheet, for sulfuric acid.
Beyond wearing latex/ rubber gloves and protective eyewear and working in a well-ventilated area, the two most important things to remember here are
- to work slowly and methodically, minimizing or eliminating spills; and
- to add acid to water--never add water to acid.
Adding water to acid can precipitously increase the temperature of the water, thereby causing it to bubble, steam, or explode, sending acid everywhere. Remember the motto:
Acid to watta, as you oughta
Finally, it is your responsibility to educate yourself about and practice adequate safety strategies and behaviors.
Ingredients
- Distilled Water. Readily accessible and cheap. Never use tap water--you'll throw your solution off from the start.
- Copper Sulfate/ Cupric Sulfate. There are two ways to go here.
- Lab-Grade Route. Because I want to minimize impurities in my bath (which build up on their own without my help), I order my Cupric Sulfate Pentahydrate from The Science Company. It comes in all sorts of sizes.
- Cheap Route: purchase agriculture-grade copper sulfate. You might be thrilled to find that Root Kill is composed of copper sulfate crystals--and it's cheap--but the impurities will throw your solution off considerably, and it is quite expensive. The cheapest I've found is on Amazon--see link below. If you purchase at 10lbs at a time, you shouldn't be paying more than $3/ lb. for it.
- Sulfuric Acid. The cheapest most accessible acid I've found is battery acid from outfits like AutoZone. As of 7.2016, they no longer sell it on their website, but they have it in their stores. You can also order the acid from Amazon (see below). Please be very careful with this stuff: practice all safety precautions, including gloves and eye protection.
- Brightener. As far as I'm aware, the only possibility here is Midas Replenishing Brightener. People have asked whether this is truly necessary, and in my experience, it is pricey, but positively necessary.
Proportions
For 1 gallon of distilled water:
32oz. Copper Sulfate
120 ml. Sulfuric Acid
10 ml. Brightener
For 2.5 gallons of distilled water
5 pounds of Copper Sulfate
300 ml of Sulfuric Acid
25 ml of Brightener
For 20 gallons of distilled water:
40 pounds of Copper Sulfate
2.4 liters of Sulfuric Acid
200 ml of Brightener
Keep in mind that
1 oz of Brightener = 30 ml
â…“ of a container of AutoZone battery acid is approximately 300 ml; and
1 gallon of water weighs 8.3 pounds.
Directions
Mix the bath no more than 2.5 gallons at a time, and in a container twice as large as the volume of water. First, pour the water into the container. Second, carefully pour the sulfuric acid into the water. Third, add the cupric sulfate crystals, and stir until they are dissolved. In the summertime, they usually dissolve in about five minutes. If not all of the crystals dissolve, no worries--all this means is that the solution is saturated. Finally, add the brightener. The solution is now complete and ready for use.
Alternate Recipe
I haven't yet tried this recipe from Robert Murray Smith, but I hope to soon. He says that all of these chemicals are food additives, and therefore safe, but I cannot confirm it. The recipe:
32g Oxalic Acid
10g Trisodium Phophate
4g Ammonium Sulphate
950 mL DI Water
See the video here.