Revised August 4, 2011

The process of electroforming is in a lot of ways similar to electroplating. It is best described as a process similar to electroplating, but one that is used in manufacturing metallic articles, rather then a means of producing surface coatings. Simply put, the difference in most cases, is that plating is a coating over a metallic item, it is a thin layer and becomes part of the work piece. Electroforming in most cases is metal built-up over a non-metallic surface, it can be quite thick and it can be separated from the mandrel or work piece as a stand alone object. Some of the common uses for electroforming are jewelry, mold making and reproduction of parts.

One of the ways that electroformed is done is by starting with a non-metallic object and using a conductive spray to cover the areas that you want the metal to form on.  After placing the work piece in a tank of copper electroforming solution, connecting it to the negative lead from the rectifier and placing a copper anode equal in size or larger than the work piece on the opposite side of the tank, 3 to 4 inches away, which is connected to the positive lead from the machine. The current is set to 1/10 of an amp per square inch of the area you are depositing the metal on. The piece is allowed to build-up on average, 2 to 8 hours or until the proper thickness is achieved. After the copper is finished you can plate over the copper with any metal finish that you want. The next step which is usually nickel should be completed as soon as possible before the copper starts to tarnish and then gold which is the most popular finish. This explains a simple set-up to help you understand the process. More complete detail and instructions for doing multiple pieces at one time is available in Dalmar's book "Everything you need to know about plating".

Bronze Baby Shoes.

Probably one of the first items that will come to mind when you are talking about electroforming is the "Bronzing of Baby Shoes". In simple terms here is how it was done: To do the process on the shoes, first, prepare the shoe by tying the laces and stuffing them with newspaper to hold their shape. Attach a couple of pieces of bare copper wire at intervals with a water proof craft glue or epoxy. Connect those wire to the negative lead on the machine. Second, dip them in the lacquer, let the excess run back in the tank but don't let them dry. Put the shoe in a bag of conductive powder or brush it on with a paint brush. When it dries, brush the excess powder off of the shoe and back in the bag. Hang your anodes on two sides of the tank about 3 or 4 inches from where the shoe will hang. Connect them to the positive lead from your rectifier. Turn on your rectifier and set it to 3 volts, then hang the shoe in the copper electroforming solution. Adjust your rectifier to 1/10 of an amp per square inch of shoe area. Leave the piece in the tank over night. Take it out, rinse it off and dry it off if you are going to a different finish. Some leave it wet so that it will tarnish and turn dark. Then use a brass wire brush on the toes and inside of the heals where a baby would wear them from crawling around. This step makes just that part look shiny. Then coat them with clear lacquer. You can use a spray for that step. Bronze baby shoes weren't bronze, they were copper.

Leaves, Sea Shells and other Organic items

Most everyone is familiar with leafs,  shells and flowers that are covered with gold sold in gift shops and tourist stops. They have had the metal electroformed right over the leaf, shell or flower and made into jewelry. Dalmar Mfg Co. was started by manufacturing electroformed jewelry back in 1971. After the line of jewelry was shown to the public, everyone wanted to know how it was made. Soon Dalmar started manufacturing machines and chemicals instead of the line of jewelry.

When electroforming on organic items such as flowers, leaves and sea shells the pieces should first be coated with lacquer, varnish or a clear plastic to preserve and stiffen them, which makes them easier to handle.

Electroforming can also be done over a wax matrix. You can carve your own or use the wax pieces that are made for casting jewelry. When working with wax make sure that you get a good connection from the lead wire to the wax. It is advisable to insert the copper wire into the wax and after spraying on the conductive coating, brush some of the conductive coating where the wire and the wax meet.

Trouble shooting electroforming

Two of the biggest mistakes made in Electroforming are (1) not getting a good connection from the lead wire to the work piece. If you are making a piece of jewelry, you should glue a finding on the piece before you start. When applying the conductive coating, make sure that you cover the glue and part of the finding to make sure that you have a good connection. If you have a work piece that is not jewelry, you should take a piece of copper wire and bend about 1/4 inch of the wire at the end to a 45 degree angle. Glue this end of the wire to the work piece in an inconspicuous place like the back of the piece. Again make sure when applying the conductive coating that you cover the end of the wire and glue to get a good connection. After you have finished the copper stage you can clip off the wire and file it smooth. For your next finish over the copper you can just wrap the wire around the piece. Don't wrap the wire around the piece when you are electroforming in copper. If you do this, more than likely you will get a bad connection and the wire will become part of the work piece due to the thickness that you are growing. A sure sign of a bad connection between the wire and the work piece is the crystallizing of the copper on the copper wire with no growth on the work piece.

(2) The biggest mistake made in electroforming is not setting the machine to the proper amperage for the area that you are electroforming in the tank or using a rectifier that is too powerful and won't adjust to the proper setting. 90% of the technical calls to our company about electroforming are due to this mistake. You must set the rectifier to 1/10 of an amp per square inch of metal surface that you are electroforming in your tank with the copper solution. If your setting is too low the copper will build-up with a shrimp color on it. If the setting is right it will come out like a new penny. If the setting is too high you will get a dark color and a bumpy finish that looks like fried chicken. Also make sure that the size of your anodes is equal or greater then the total of surface that you are electroforming in the tank.

Electroforming kits can be found here.

Electroforming chemicals can be found here.

Combination Kits can be found here.

An explanation of the difference in tank and brush plating.

"Believe"