Electroforming can seem daunting, especially when you see some of the amazing things people can create. Fear not, we have you covered! In this section of the website we will guide you through the entire process, from deciding what setup you need to setting up the kit and electroforming items.
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1. What Is Electroforming?
What is electroforming? Well, as you are reading this you will probably already roughly know what electroforming is. In essence, it is the coating of metal onto an item that is usually not conductive, through the use of an electrolysis cell. Most commonly, electroforming is done using copper. It is not only an easy metal to deposit due to a large range of currents and temperatures at which it can be deposited, but it is has a great throwing power and many great mechanical properties which make it idea for a base material. It is also very inexpensive to run.
In general, the word electroforming has come to represent the collective term for applying copper as a metal, onto objects that are usually non-conductive. The image to the right is a perfect example of the colloquial use of electroforming. An item of Lego, made from non-conductive ABS plastic, has been coated with copper through the process of electroforming. More specifically however, this is technically electrofabrication. The work, the item being electroformed, becomes part of the final product. In true electroforming, the item that is being deposited onto is removed, leaving behind a final product that is solely metal. The wording however, is only important in small circles. If you were to mention electroforming to most people who have a small amount of knowledge on the subject, they will known what you mean.
2. What supplies do I need?
The tools required for electroforming can be broken down into essentials and extras. These items (except water) are conveniently measured and supplied in one of our electroforming kits.
PPE: gloves, goggles, mask
Electroforming tank: PP or HDPE plastic or glass
Electrolyte chemicals: copper sulphate, sulphuric acid
Water: distilled, deionised or pure water (not tap water)
Brighteners and Levellers
Electrical connectors: wires, copper wire, bus bar
Power Supply: 0-15V, 0-5A, adjustable
Anodes: PDO copper (not scrap copper or copper pipe) composition: copper > 99.9% phosphorus 0.04-0.06%
Anode Bags: PP rated below 10 microns (ideally 1 micron)
3. How do I keep myself safe?
The absolute most important aspect of the entire electroforming process is safety. Please, please, please do not skip or miss any safety steps. Doing so, either at the beginning of your electroforming journey, or during, may cause serious harm to yourself or others. If you have been electroforming for quite some time, please do not get complacent as safety should be and is always the most essential step to follow.
The absolute minimum safety precautions needed for electroforming are; PPE, adequate ventilation, a safe electroforming area, neutralising solution and an undisturbed space.
Hazards & Risks
The main sources of risk, hazards, associated with electroforming are the chemicals in the electrolyte and the electrical circuit.
Material Safety Data Sheets (MSDS) can be downloaded from our website or from different online sources. These give a clear and concise description of the chemicals and their associated hazard identification.
Gloves should be worn at all times! Not only will wearing gloves protect your hands from potential chemical exposure, but it also prevents the spread of contaminants onto your items and into the electroforming tank. On a personal note, we would advise again disposable and single use gloves as they have a negative impact on our world and environment.
Goggles should be worn whenever chemicals or electrolyte are in use. This includes initial mixing, filtering, maintenance, rinsing and especially when placing items into and removing items from the electroforming tank.
The main function of masks is to protect your airways; your mouth, nose and throat. Masks should be used at the time time as goggles; initial mixing, tank filtration, etc. They should also be used when the ambient room temperature is lower than that of the tank. When this temperature difference occurs, liquid will evaporate from the electrolyte with the potential to take other chemicals with it. A mask should also be used when painting with solvent based paints or sealers. Finally, if the environment in which electroforming does not have adequate ventilation or if there is no direct extraction masks should be worn.
Creating a safe environment to electroform in is important in regards to keeping yourself and others safe.
One thing to consider before setting up your own tank is where it will be placed. Having the electroforming system in your house is not advised unless you have all of the safety precautions in place.
Below is a list of questions and advised answers to help think and setup an ideal electroforming area.
Will you be electroforming inside your house or outside in a shed/workshop/garage?
Is there already a clear space to electroform in?
Is there any form of ventilation already? (e.g. doors, windows or extractor fan)
Will your electroforming area be disturbed?
Is there anything close that will be affected by fumes or accidental splashes?
4. How do I set up the kit?
For full instructions on how to setup the kit, including electrolyte mixing, follow the instructions included with the kit.
As a general guide, the workflow for setting up a 5L kit should be:
Warm 3.5L of distilled water with the heater
Add each of the electrolyte chemicals individually and stir until fully dissolved
Connect anodes, insert into anode bags and immerse in the electrolyte
Connect the anodes to the positive of the power supply
Connect your items to the negative of the power supply
Insert internal filter if using
5. Sealing, Paints and Painting
Proper preparation is paramount particularly when painting precious parts. Spending the extra time to seal and paint, and let both processes fully dry will reduce the chances of failure and make the results more consistent.
Initial Item Inspection
The first step in preparing items of for electroforming is an inspection. This is mainly to observe three things; fragility, cleanliness and porosity. Items that are fragile, like flowers and feather, will need extra attention to maintain their shape and appearance. Applying a light sealer, such as hairspray, will help to make softer items more rigid before sealing and painting. Cleanliness of the items is also important, especially for found objects. By removing any surface soils and debris, you will reduce the chance of a potential failure further down the line. Checking an items porosity is critical in preventing a problem known as bleed out. This occurs when the electrolyte is absorbed into an item and then bleeds out slowly once electroforming has been completed. If your item is really porous, make sure to apply extra sealer.
Sealing is in most cases, the safest (in regards to obtaining the best results) first step in electroforming. Sealing porous items is critical but sealing organic items and some crystals is just as important. Organic items can and will be affected by the acidity of the electrolyte. More robust organic objects like wood, nuts and seeds will not be affected to a large extent compared to softer organic such as petals. Inorganic items - shells, rocks, crystals, plastics etc. - should also be sealed.
Sealing is in most cases, the safest (in regards to obtaining the best results) first step in electroforming. Sealing porous items is critical but sealing organic items and some crystals is just as important.
Organic items can and will be affected by the acidity of the electrolyte. More robust organic objects like wood, nuts and seeds will not be affected to a large extent compared to softer organic such as petals. Inorganic items - shells, rocks, crystals, plastics etc. - should also be sealed.
There are a lot of conductive paints available to buy, however, there are three main types that are determined by the conductive ingredient: graphite, copper and silver. Nickel and ferrous paint can be used but they are not as suitable as the three above.
Graphite paint is very common among home electroformers. It is very inexpensive and the particles of graphite are very small, allowing for the preservation of surface detail. There are a few disadvantages to using graphite based paint. The first is that, when mixed with other paint ingredients, graphite paint has a lower conductivity, leading to a few other problems. The lower conductivity means that copper slowly grows from the point of contact to the rest of the circuit. See image 3.4 for a visual demonstration of this effect.
The next type of paint is copper. There are two main benefits to using copper paint; low cost and high conductivity. These two advantages couple to help you create lower cost items quicker than graphite paint. The major downside to copper paint is that as soon as it has been painted, the copper particles will slowly start to oxidise. The graph shows how this oxidisation effects conductivity when compared to graphite and silver paint.
This is the best paint overall (in our opinion) due to its super high conductivity and very small particle size. When electroforming, copper will be deposited onto silver paint in 2 - 5 minutes rather 15 - 60 minutes you would get with the others. The paint is expensive because of the silver content, however, a small amount goes a long way. Air brushing is a great way to apply the silver paint, but the process is wasteful as some paint will not reach the item being painted. This can become expensive with silver paint.
Sealing and Painting Methods
There are numerous ways of applying a sealer and conductive paint and the method chosen is determined by the items and your personal preference. These methods are (but not limited to):
Immersion: delicate items or other items that are difficult to paint can easily be fully covered with this method. The only downside is that drips occur often and so steps should be taken to remove excess sealant.
Paint Brush: this is probably the most common method. It is very controllable as the sealer or paint is only applied in the areas brushed.
Air Brush: this is a Gateros favourite, it is not only controllable but the layer of sealer or paint applied can be very thin and very even. Ideal for items that are intricate and need surface detail preserving.
Make sure to always shake and mix paints really well! The conductive material tends to settle at the bottom, meaning if you only dip your paint brush in, it won’t apply a very conductive layer to your items.
Current density is the driving force for the deposition of copper and determines the total amperage needed from the power supply. As a simple rule, when you first put your items in the tank, when they are covered with conductive paint, the current density for copper should be 0.05 amps per square inch (1 inch2 = 6.45 cm2). Inches are used as it produces a clean, whole number.
For more information on current density, the anode sun analogy, edge effect and object orientation, check out our electroforming ebook!
Due to the current taking the path of least resistance and the varying current density across the surface of an item, the orientation of an object is important in achieving the finish you would like. To achieve a uniform deposition of copper across the whole surface area of an item, it should be located as far away from anodes as possible, or as centrally between multiple anodes. Different textures and finishes can be produced by manipulating object orientation and thus the areas of high and low current density. Take the 3D printed dragon in the image below as an example. It’s head has a lot of texture, caused by fast copper deposition. It was orientated with its head facing and closer to one anode. The head therefore, had higher current density than the rest of the body, which has a nice, uniform layer of copper.
Items must be connected to the power supply, that is, the conductive paint must form part of the circuit. This is most commonly and most easily done using copper wire. There are a number of ways of attaching copper wire to your items. As long as the wire is in contact with the conductive paint, electroforming will occur. Some ways include; wire wrapping, drilling and glueing, crocodile clips, hooks, and baskets.
Before turning on the power, a few checks should be undertaken. Make sure the pH is below 1. The temperature is above 15ºC and below 30ºC. There is some agitation in the tank (can be simply mixing with a plastic spoon every 30 mins). Filtration, if using, is on and is working correctly.
7. The Electroforming Process
Before beginning, ensure adequate PPE is on; gloves are a necessity. Goggles may be needed if you are placing a large item in the tank that can cause splashes. A mask should be worn if there is little to no ventilation removing the vapours.
Make sure the pre-electroforming checks, from the previous section, have been performed - most importantly, that the tank is up to temperature. Also, make sure that the power supply is turned off and the current is set to zero. The voltage setting can be set anywhere as the voltage will change depending on the current used and the surface area of items in the tank.
If the paint has fully dried (24 hours at room temperature or 2 hours at 60°C) then the items can be attached to the bus bar and placed into the tank. At this stage, before the power is turned on, take note of their orientation. The orientation of parts will play a role in the final finish and the location of copper deposition. Refer back to the previous chapter to determine the orientation needed for the finish required. It is also important to know that objects of different sizes will electroform at different rates if placed in the tank at the same time. Again, refer back to the previous section for more information.
Before turning on the power, it is time to check the total surface area and estimate the current needed. As a reminder, the current density of copper and silver are:
- Copper: 0.05-0.1 A/inch2
Silver: 0.03-0.12 A/inch2
Once the current needed it is time to turn on the power supply. After turning the power on, slowly increase the current from zero to the required number.
Once the items are in and the power is on, you can leave them for a long while. It is, however, better to monitor and check the items especially in the first few stages.
The first check should be performed in the first 5-15 minutes. At this stage, depending on the conductivity of the paint, there should be some small copper deposits. They will look dull and pink and this is normal. If you are using graphite paint it may take up to 2 hours to begin depositing copper.
The second check should be performed between 20-30 minutes. From here you should begin to see most of ht either become covered in a dull copper. Again, this is dependent on the paint being used. If the items are really shiny at this stage, it may indicate that the current is too high.
After this, feel free to leave your item as long as you need. It is still a good idea however, to return periodically to either move the item, so that it doesn’t bond to the hanging wire, or to get a more even coverage of copper. It is also a good idea to regularly check the progress in case any problems occur.
The following list is organised in terms of the most likely problems that will occur when electroforming. For almost all problems, brighteners will need replenishing and this should be done as common practice when you notice the results start to fall off.
Low Brightener Levels
Symptoms: The newly electroformed layer will look dull, pink, rough
Causes: Low level of brightener. The brighteners will be codeposited with the copper and become part of the new surface. This means the levels of brightener decrease as you do more electroforming
Fixes: Add more brightener and test. 10p Coin Test: Take a 10p coin (or a piece of nickel) and clean it well with warm water and soap - this removes traces of grease and oils. Clean it with wire wool, wire brush, sand paper - this removes any dark oxides. Rinse well in water. Electroform for 10 minutes. The coin should look bright and shiny with a new layer of copper. If the surface looks like the symptoms above, add more brightener into the tank and repeat this test.
Prevention: Observe brightness of your items after electroforming and add more brightener if they are beginning to look dull. The good thing is that you cannot add too much brightener (unles you add litres of it). Having extra brighteners will cause the copper to look extremely shiny!
Symptoms: Slightly higher current will form nodule on areas of high current density. Very high current can cause: dullness, roughness, destruction of brighteners
Causes: The current setting is too high for the surface area of items in the tank
Fixes: Unfortunately, if the item has been burnt due to high current the only way it may be salvaged is with sanding and buffing. Dull and pink items can be salvaged by adding more brighteners into the tank and electroforming for longer
Prevention: Work out surface area before plating and set current to 0.05A per square inch. Use a lower current to start with and increase it if needed. Having a low current will not affect the copper deposits, it will just take longer to electroform. Recite the electroforming catchphrase: “Low and slow”
Low and High Temperature
Symptoms: High Temperature: dull, rough, pink (destruction of brighteners). Low Temperature: slow electroforming, patchy electroforming
Causes: Temperature is too high. Temperature is too low. Outside of the working temperature range of 15ºC - 30ºC
Fixes: Heat or cool the electrolyte. Add more brightener and test using 10p coin test above
Prevention: Check electrolyte temperature before placing items in the tank
Symptoms: Multicoloured staining and oxidisation on the surface. This however, can be a nice and unique effect sometimes!
Causes: The electrolyte has not been completely rinsed off an item
Fixes: Rinsing the part in acid (such as jewellery pickle) will remove any oxidisation and staining on the surface
Prevention: Rinse well and change rinse water once it becomes contaminated
Copper Conductive Paint
Symptoms: Rough electroformed surface. Patchy or no electroforming
Causes: The rough electroformed surface will be caused by adding too little copper paint. The copper flakes within the paint will not have settled on the surface to become smooth. Once painted and fully dried, the copper in the paint will start to oxidise and drop in conductivity until it becomes completely non-conductive
Fixes: Unfortunately, the copper paint cannot be activated again so another layer of paint needs to be added
Prevention: Apply copper paint so that it looks wet on the surface of the items. Electroform items as soon as the copper paint has dried
Poor Electrical Connections
Symptoms: Fluctuating amperage - this will cause slow electroforming that appears dull, rough and patchy. Amperage is at zero while voltage is at maximum leading to no electroforming at all
Causes: The circuit has been broken
Fixes: Check each connection, especially those near to the electrolyte (e.g. anodes and bus bar). The copper will eventually erode away due to the vapours from the electrolyte and creeping copper crystals
Prevention: Regularly check the electrical circuit and replace wires that are starting to degrade.
Excess Copper Sludge
Symptoms: Brown sludge at the bottom of the tank or in anode bag. This sludge can also be deposited onto your item, causing roughness and nodulation, when there is agitation but no filtration
Causes: Normal non-uniform dissolution of the copper. Impure anodes containing no phosphorus. Anode Polarisation due to too much copper in the tank leading to extra corrosion of the anode. No filtration and agitation. Anode current density too low; too many anodes in the tank; anode-cathode ratio too high. Low chloride content in the bath
Fixes: Filter the solution. Batch filter through fine filter material. Continuous filtration with internal/external filter unit
Prevention: Maintain correct anode-cathode surface area ratio; close to, but not below, 2:1. Allows for formation of phosphorus film on anode which reduces excess corrosion. Use anodes containing phosphorus; not just copper wire or pip. Constant agitation and filtration. Maintain correct levels of copper and/or acid in g/L.
Poor Micro/Macro Throwing Power - ability to fill cracks and holes
Symptoms: Surface imperfections are not filled - scratches, holes and marks are still visible
Causes: Too high copper content. Low acid concentration. Low Brightener/Leveller concentration
Fixes: Add more brightener and test using 10p test. Add a little more acid and test. Perform a plate out of the high copper content - low current over 12 hours on large steel sheet.
Prevention: Keep levels of brightener topped up.
Symptoms: Blue crystals, Staining, Oxidisation. All of the above may not appear until a few days after electroforming
Causes: On porous items that haven not been sealed properly, copper electrolyte has been absorbed into item when in the tank. When the item is taken out, the solution migrates through the copper lattice to the surface. The water from the solution evaporates leaving copper sulphate crystals
Fixes: The crystals can be dissolved in hot water but they will still eventually always bleed out again. Another hot and cold alternating rinse may help to purge more trapped electrolyte.
Prevention: Seal everything and make sure items are sealed well or add multiple coats of sealer. Make sure the sealer you are using doesn’t dissolve in the electrolyte. A thicker copper layer (longer electroforming) will act as a bigger barrier and will take more time for the trapped copper to migrate through. Hot and cold water rinse immediately after electroforming. This will contract and expand the surface and purge a lot of the solution.
1. Take items out of the tank and rinse them in near boiling deionised water
2. Then rinse in fridge cold water
3. Alternate for 3 rounds
High Chloride Content
Symptoms: Anode polarisation, leading to more anode sludge. Roughness of the deposited copper on the cathode
Causes: Too many chloride ions in the solution
Fixes: Dilute the solution by mixing in more, mixed electrolyte
Low Chloride Content
Symptoms: Burns on high current density areas; areas closer to the anode, edges of items, peaks of items. Areas where there is more electrolyte surrounding the item. Pitting - small holes in the new copper layer
Causes: Too few chloride ions in the solution
Fixes: Add more chloride to the solution. Sodium chloride is sufficient (table salt).
There are a large number of processes that can be applied to the newly deposited layer of metal. The first and most important is the process in the previous section, rinsing. Once rinsed and dried, an item can then be sealed to retain colour, shininess and prevent oxidisation, plated with another metal such as gold or silver, given a patina to change its colour and texture, or simply left to naturally age.