These notes are from a workshop given by Maria Phillips at the Enamelist Society Conference in Olympia , WA in August 2003.
Available at most jewelry supply outlets. The size will vary according to the size of your bath. In most cases, a small rectifier will be sufficient for the individual artist.
This is where you house your bath. It is important to have a pan of some sort underneath your tank (of sufficient size to accommodate the liquid should your tank leak). Since the bath is acid, all necessary precautions MUST be taken.
The size of the bath must correspond to the rectifier. You cannot have a huge bath and a small rectifier. The tank must be made of glass, polypropylene or polyethylene plastic. Plastic is preferred because there is less chance of breakage. You can get a plastic container from the plastic supplier in your community. A glass tank can be obtained from a fish or pet shop. Be aware of leakage. Fish tanks are put together with plates of glass and silicone. Remember, your bath will house acid, which could do serious damage if it leaks. Have your fish tank in another container that is acid proof in case the system leaks. Another possibility for a tank is a truck or automobile battery case. These plastic shells are designed to contain batteries and resist acid. They are easily and inexpensively obtained from auto parts stores.
These are metal bars that support the anodes and cathodes. You will need anywhere from 2 to 3 bus bars, depending how many anodes you have. These bars should be metal and capable of conducting electricity. You may want to use a non-corrosive material. She uses copper .25 round stock and flattens one end of it so that the alligator clips have more surface area on which to attach. The bars need to be sturdy enough to support both your work and the anodes.
You need a filtration system. These must be bought through the industry and are expensive. The filtration system helps maintain the chemical balance of the bath and promotes circulation, which assists in plating and filter out surface debris. Because the bath is acid, it will attack and degrade a common store-bought filter. This would contaminate your bath. The carbon that is a part of most common filters will deplete your bath of any organic substance, including your brighteners. You will have to replenish them if you choose this type of filter. Organic materials affect the chemical makeup of your bath quicker over time than wax or plastic materials. You may need to consider filtering your bath every four to six months, depending on how much you are using it. Once you have filtered it, you will need to replenish the brighteners.
Note: You are working with hazardous materials. They must all be neutralized and disposed of properly at a hazardous waste location in your city. This includes the filter, which must also be neutralized before disposal in the proper site.
This system provides a constant source of circulation while you are running your bath. You need to find an air pump that is of sufficient size for your bath. A low cost system can be purchased at the fish supply store. You can create an agitation system out of PVC tubing and a fish tank air system. If you use PVC tubing, drill holes in it to provide circulation.
The bath needs to be kept at a temperature of 75 – 80F. Heat assists the chemical process. A simple glass fish tank heater will work. Make sure you buy one that is capable of heating your size tank and that any plastic parts of the heater cannot be submerged in your bath, because acids will dissolve plastic and contaminate your bath.
Phosphorized copper must be obtained from a distributor, specifically a plating company. Anodes should be 1.5 to 2.5 times the cathode area/size.
They are used to suspend the anodes and are non-corrosive.
These should be napped polypropylene or dynel. They assist in filtration, plating and containing the phosphorous layer/deposit that the anodes shed during the plating process.
Making the Bath Solution
|What You Will Need:||For 20 Gal. Bath||For 10 Gal. Bath|
|Liquid Copper Sulfate||12 Gallons||6 Gallons|
|Sulfuric Acid||2400ml or 2.4||1200ml|
|Hydrochloric Acid or Muriatic Acid||12 ml||6ml|
|Brighteners *||300 ml||150 ml|
|Distilled H2O||approx. 5-7 gal.||approx. 1-3 gal.|
|* Brighteners will have to be monitored and added regularly. If you detect depletion (your objects will be dull) then .5 ml to 2 ml per gallon can be added. Add a small amount and test.|
A pre-mixed solution can be purchased of the above bath solutions.
Setting Up The Bath
All your equipment needs to be cleaned. Fill and soak the tank and agitation system with a solution of sulfuric acid and water. Proportions are 10 to 1. So a 10% solution of sulfuric to water and soak for at least 42 hours. The heater, anodes and polypropylene bags can be put in the bath for the last 24 hours. Rinse in a bath of distilled water before placing in the bath.
This is a hazardous procedure, so wear protective gear: eye protection, rubber gloves, rubber apron, and a respirator. Always have neutralizer on hand and proper ventilation.
Preparing Objects for Electroforming
A lead wire must be attached to your object. This must be a copper wire that conducts electricity. Any copper electrical wire will work. Glue the wire to the object with two-part epoxy, and dry. Dip the object into clear lacquer, dry. Repeat the lacquer dip, and dry.
Paint the object and the connection section of the lead wire with a copper and water based conductive paint (Metalform and Electrodab are two commercial products). These products are sold by various suppliers. This copper surface permits the plating process to adhere to the organic or wax models that are immersed into the bath.
Attach the lead wire to the cathode. Make sure all connections are secure. If the connections are faulty, the system will not plate.
The length of time it takes to electroform will be determined by the size of the bath and the size of the object. This is a very slow and time-consuming process. We have small objects in the bath for several hours and even overnight.
When you are loading the bath, use rubber gloves and turn off all electrical current. Hang everything securely, remove your hands, and then slowly turn on the current. Remember, you are working with electric current and acid. Do not take chances.
If you are electroforming a soft object, such as a fabric, first stiffen the fabric (Gack 400 was recommended).
Electroforming is a highly technical process, and you must balance your bath before you can be successful. Once you have done that, and have properly prepared your pieces for electroforming, the rest is most enjoyable. I hope these notes help someone, and I would also like to recommend reading about electroforming in the various metalsmithing books that are readily available from the public library.