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Problems and solutions for copper electroforming

A discussion started in 1995 and continuing through 2017 . . .

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March 5, 2016

Q. I have been getting into electroforming, but have run into a few snags along the way.I have multiple questions.

1. I have a magnetic stirrer with heat. Is it better to electroform with warm solution or cold? (I get a better current when its warm)

Copper Sulphate 10 pounds

2. What should the current and voltage be if I'm doing a bunch of small rings at once? It seems to more all over the place. Sometimes the current will just stop working all together in the middle of a plate. Any idea why?

3. I heard Root Kill is basically the same things as the solution you get at Rio grande. It this true and is it safe to use. It's 99.9 percent copper sulfate.

4. I've been getting some uneven pieces and am not sure why. I use gloves to touch the pieces to ensure there is no oil or dirt on them while I'm painting them, but seem to still have some places that won't plate. Any cleaning solutions I could try before I paint?

5. Do you know how to make your own conductive paint or glue. I can't find one that I like.

6. How often should I be changing the copper solution and anode?

Thank you for any info you might have :)

Megan Carli
- Brooklyn, New York

Foam buildup from aerating my copper plating solution?

March 13, 2016

Q. Guten tag from lovely Rostock, Germany! I am an electrician by trade but also an avid fan of making copper jewelry. I was really excited to try out this crazy "electro forming" all the kids are talking about, and last week acquired the various bits and things I needed to get started. In my haste and excitement my first attempt was a total disaster, upon which I found and read through this forum. Thank you so so SOOOO much for all the great questions and answers! I actually literally found solutions to all my issues here! What a great resource!

I DO however have one question.... I bought a small aquarium pump, but found that if I leave it on continuously, a layer of foam builds up at the top of my solution which left unchecked would flow over the top of my beaker. Do you have any suggestions as to how I may remedy this?

Also, since I am already asking questions, what is the lifespan generally speaking of the solution itself? Like, specifically if I am doing small pendants approximately 2 square inches of surface are for a time of 6 to 8 hours each at 0.2 amps.... roughly how many times can I repeat this process before I require new solution?

Thank you again for all of your great help!

Ian Mccallum
hobbyist - Rostock, Mecklenburg Vorpommern, Germany

The Canning Handbook of Surface Finishing Technology

March 2016

A. Hello Ian. There are wetting agents made for air agitated plating baths to prevent this foaming; the supplier of your copper plating bath should know about them. Electroplating baths are "equilibrium processes" which are designed to -- if all goes well -- run forever; in industrial applications, copper plating baths are filtered, and various purification steps are taken as needed, and the plating bath is almost never dumped and re-made.

If your library has a copy of The Canning Handbook =>
it has a good chapter on copper plating, and another good one on electroforming.


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Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

March 8, 2016

Q. Hello I just bought a rectifier to start electroforming/electroplating copper onto geode stones. I know of the materials I need, but I do not know what is the difference between bright copper electroforming solution vs. Bright copper electroforming with Acid. What is the purpose of the acid? Do I need it? Thank you.

julie afzali
- brooklyn new york USA

March 2016

A. Hi Julie. I suspect that nobody except the particular vendor who is offering that solution can tell you what it means. Both solutions are probably "acid copper sulphate" based.


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Ted Mooney, P.E. RET
Pine Beach, New Jersey

March 21, 2016

Q. I recently moved. When I did, I bottled all of my electroforming solutions in their original bottles and boxes, packed them away and had hopes of reusing the solution once I got my studio back up and running.

I am using a small 1 gallon fish tank to electroform which uses a fish filter/air pump for agitation. I am using silver conductive paint and a large piece of copper for an anode. In the past (after the first hour) I could see the plating happening and could just let it do its thing. My piece has been in the bath for over 12 hrs now and has barely any plating, and that is salmon in color. It seems to be happening a lot slower than in the past. Although I switched the containers I was using, they are the same size and material so that doesn't seem like it should create any problems. Do you have any idea what could be the issue? I guess I'm going to let it keep going but its highly frustrating. Do I need to add acid to the mix? Please help!

Alexandra Camacho
Art/jewelry - los angeles, California, US

March 21, 2016

A. Alexandra: It sounds like you are getting little if any current flow. Check that all electrical connections are clean and tight. It would be best if you had an ampere meter, but even a simple DC volt meter will help. You can pick one up at a big-box hardware store that will read low voltages. Depending on your setup, you'll probably need 2 or 3 volts. Or if you can measure amps, maybe 4-8 amps per square foot of surface being plated.

Are you certain you don't have the connections reversed?

(+) to the anode (-) to the part.

jeffrey holmes
Jeffrey Holmes, CEF
      South Carolina

March 21, 2016

Q. Hi!

Thanks for responding. I use a digital rectifier and I always have used it on the lowest setting and has worked fine for 1-3 pieces up until the move. I turned it up to .85 and the the other setting changes along with it to compensate I guess? Do I still need to check the amps and volts if it's showing current on my rectifier?

Alexandra camacho [returning]
- Los Angeles, California

March 23, 2016

Q. Hi, I just started electroplating and I am running into issues! I am using a 3 amp rectifier with the solution from Rio and a conductive solution from safer solution. This is my second try and it came out worse then the first! The copper seems to not be bonding to, well, anything! It is just balling up on my piece and wipes right off! The first piece came out mostly okay and half did just the same, just wiped off. It is coming out the right color so I'm not sure what I'm doing wrong. Any help would be greatly appreciated!

Jennifer peone
jewelry - Hauser Idaho usa

March 2016

A. Hi Jennifer. Pretreatment is 90% of plating for most people. What is your jewelry made of, and how have you assured yourself that it is spotlessly clean and properly activated. If the jewelry is a conductive metal, why are you coating it with conductive solution? Your problem may be in the plating tank, but it may not be.


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Ted Mooney, P.E. RET
Pine Beach, New Jersey

March 23, 2016

Q. Ted,
Thank you for getting back to me so fast! So I am using a two-part epoxy to set stones on a small pendant that is on a bale made of copper. I am O l painting the epoxy and the copper is cleaned before placing it into the tank. As far as my set up goes I have it in a large half gallon glass jar with, I think, copper coiled inside of it. According to my rectifier I am getting a good flow.

Jennifer peone [returning]
- Hauser Idaho usa

March 30, 2016

Q. Thank you for this opportunity to express my problems. I have a small artist studio and my problem is trying to electroform concave areas on silicone rubber mold with a copper solution . I have the correct paint but it looks like it's peeling off most of the time, the top areas of the mold are getting plated well but the lowest ones are not and my question is what am I doing wrong. the liquids that I use for my tank are coming from a professional distributor here in Los Angeles and my tank size is 3 feet by 2 feet by 2 feet I'm using a rectifier with a range up to 100 amps so I've got plenty of electricity. My molds are usually in the vicinity of 8 inches x 4 inches. I am using the formula of 1th of an amp for every in of plating surface. I will really be happy to get an answer to my problem thank you.

mario jason
sculptor - sherman oaks, California, U.S.A.

Ed. note: There was a typo in your posting, Mario. Perhaps you meant 1/10th of an Amp/sq. in.?

March 2016

Hi Jennifer, Hi Mario. The basic issue for jeweler-hobbyists is that if all goes well the electroform works, but if there is a small slip in any of a hundred little things they're not likely to have any idea what to do to correct it because they have little relevant experience.

Even Renoir and Monet did charcoal sketches before trying to commit a scene to oil. So practice on some old coins. Buy some Hull Cell panels and plate them. Bend them in half to see how well the plating sticks. Plate them at 5X your present current density, and at 1/5, and see what happens. Scrub them with pumice before plating. Apply some masking material to see the strengths and weaknesses of approaches. There is no substitute for experience.

Jennifer: after you've practiced with copper panels, paint some stripes of that epoxy on some flat copper panels so you can really see what is going on with regards to the adhesion.

Mario: The amount of plating deposited at any spot is proportional to the current flowing to that spot, and the current takes the shortest path through the solution from the anode to the cathode. Are you sure the anode is no further from the bottom of the mold than from the top areas? If the paint is not sticking to the rubber and you can't make it stick, I'm not so sure that it's "the correct paint".

Luck and Regards,

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Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

May 12, 2016

Q. Hello and thank you for a wonderful forum. I am trying to copper plate baby shoes, dummies, bottles, etc., and have been experiencing about 4 issues that may or may not be solved with one solution. Ok here goes....
1. When I place my cathode/job in the tank the amps start where they should depending on the size of the cathode but after about 5 mins they start dropping. Slowly at first and then quite rapidly, and within 7-8 mins the amps are down to 2-0.2amps. If I leave it alone, sometimes it creeps back up to around half of what they initially where. What can I do to stop amps from dropping? The solution is brand new from one of the largest reputable suppliers in the country. The rectifier has been checked and it's perfect. I have good agitation and I'm using phosphorus copper anode in anode bags. The temperature of the bath is around 23 °C. So I go around in circles ... the solution company says it's the rectifier, the rectifier guy says it's the anodes, the anode company says it's my application ... and around we go again!
2. I'm not getting a nice black coating on the anodes. It's more of a reddish brown colour and I see this reddish brown silt seep into the solution through the anode bags.
4. I sometimes get those blue crystals which I believe are copper sulphate crystals on the anode which is inside the anode bag.
3. I'm not achieving a nice bright finish. It is consistently a dull pink/salmon colour.
As i said, I'm not sure if all these issues are related to one problem or if they are all separate problems. Any advise will be greatly appreciated. Thanks again for a wonderful informative forum.
Kind regards,

Cherissa Sayanna
Tinker - Durban south africa

May 24, 2016

Q. I've been Electroforming with ease for a few years now; however, lately my pieces are coming out of the bath glittery and very brittle.
I had been using some copper tubing as an anode which I don't believe to be that pure; I've since switched to a more pure copper sheet. I also added maybe a bit too much brightener just before I started getting my poor results.
So my question is, what is causing the glittery and brittle plate. Too much brightener? Or possibly depleted copper solution from using an alloyed anode? And what would you suggest to fix this? Thanks so much!

Kelsie Anne
- Alberta, Canada

May 2016

Clean Earth Copper Plating Solution

A. Hi Kelsie. Too much brightener is probably the chief problem, although maybe not the only problem.

What works to remove many/most brighteners is carbon treatment, hot, and possibly with peroxide first. Your copper plating solution should have a technical data sheet that talks about this. Treatment must be done in a separate tank and then filtered back, because you'll "never" get the carbon out if it's in your operating tank.

If this sounds too technical, or like too much work, replacing the solution is probably an option.


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Ted Mooney, P.E. RET
Pine Beach, New Jersey

Salmon pink vs bright copper finish from electroforming

September 27, 2016

Q. My setup:
-- 30V/5A variable DC power supply
-- Midas bright electro-forming copper solution (1qt)
-- small glass container roughly 5"x3"x5"
-- anode is a length (approx. 30") of 1/8" diameter copper wire, which I've bent into a shape that ramps up the sides starting at the bottom
-- cathode/workpiece is a thin wax model (properly painted) roughly circular in shape, about 3" x 3", front and back
-- initially no agitation, but have since added a couple of small bubblers at the corners

I am having trouble getting a bright finish to show up. My very first piece did seem to come out bright (mainly along the edges), but every piece (maybe 3 or 4 pieces) I've tried after that has not.

If memory serves, I had set my power supply to 1V for the first piece (the resulting current was around 2.5 A). While that was plating, some online reading led me to the suggested target current of 0.1 A per sq. in. of cathode. Which for me, would have been: 3 x 3 = 9 sq. in. x 2 sides and considering it was a thin model, = 18 sq. in. total ... so 1.8 A is what I should have been aiming for. So I ended up turning the input voltage down until I hit 1.8 A. This seemed to have resulted in a less bright finish when I finally pulled the piece out.

For subsequent pieces, I tried to target the 0.1 A/sq. in. current value by adjusting the power supply voltage. But I've ended up with salmon pink finishes every time.

I've only plated 4 items (all roughly the same size) ... surely my solution is still good, right?

I have read on here (and on other sources) that if your finish is salmon pink, this usually means that your current is too low. But if I raise the current, I'll end up over (way over) the 0.1 A/sq. in. recommendation. I tried it anyway on one piece and it didn't seem to affect the finish.

If I notice a salmon pink finish developing, and assuming I knew what the proper voltage/current adjustment to make, can I make the adjustment and expect to "correct" the finish (i.e., get a bright copper finish at the end)? Or once "you go salmon, you can't go back"?

Same goes for pulling the item out of the bath to inspect it ... am I risking ruining my finish by pulling the item and putting it back in every 30 minutes?

Using the 0.1 A/sq. in. guideline, results in a target current of around 1.8 A, which usually results in my voltage being around 0.5 V. Am I understanding that guideline correctly? Half a volt seems so low ...

Any suggestions on what I might be doing wrong such that I keep ending up with a salmon pink finish? (I know I can polish after the plating has completed, but I'd like to come out of the bath nice and shiny to start with.)

Thanks in advance for any answers/suggestions/comments/etc.

jim cisco
- austin, Texas, usa

October 4, 2016

Q. I had a similar problem but I did not have brightener in my bath. After I added about 5 ml of Midas Copper Brightener to the bath of approx. 1 gallon of used solution my results were smoother but with striped ridges in the copper plating. I did a test with a quarter and the plating is intact but with vertical stripes all in the plating. My amps were set to .02-.1 range during the test. I turned off air agitation to see if this would change results but it made no difference. Can this bath be saved or should I throw it out? Thanks.

jamie stephens
- Birmingham, Alabama usa

October 2016

A. Hi Jamie. From the safety data sheet it appears that the Midas Copper Brightener is not an organic brightener in the sense that I and many others would use the term 'brightener', but is actually basically a re-charge of the sulphuric acid content. And it sounds like you might now have too much acid content. Do you have any analytical capability, maybe a pH meter or pH paper would even give a hint. The acid can probably be reduced by electrolizing at high current density (as hydrogen is released, the pH should drop) or by the addition of copper carbonate (but I don't know if you have the materials and knowledge to undertake that).


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Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

October 7, 2016

A. Midas plating products are intended to be used in a table top operation with small tanks. Within this context controlling the current density with voltage values works very well. I suggest that you operate this copper bath between 1 and 2 volts as is recommended on the product label and let the amperage find its own level.

Neil Bell
Red Sky Plating

Albuquerque, New Mexico

October 9, 2016

Q. Ted, what ph level should the copper bath have?

Neil, my rectifier is strange. I usually crank the volts all the way up and set my amps. The rectifier then adjusts volts to keep current. I will try this solution, but my amps maybe very high to trigger rectifier to run at 2 volts.
Can you suggest an additive for bigger tanks, say up to 1 gallon of bath to improve plating texture?

jamie stephens [returning]
- Birmingham, Alabama usa

October 2016

A. Hi Jamie. It turns out that my knee-jerk reply that you might check the pH was probably not useful; although pH is monitored in most plating baths, it turns out that none of my references even suggest a value for acid-copper electroforming solutions. Although the pH is probably about 1.0, it doesn't seem that you'll be able to tell from the pH whether you added excess acid.

Most professional platers don't attempt to add their own brighteners, but rely on the technical data sheet and recommendations of the supplier. Without an analytical laboratory, it would be a very bad idea; you have to rely on Midas.

It is not possible for the rectifier, no matter how it's designed, to adjust amps and volts independently. A given surface area and anode-cathode distance (and a few other factors) mean that the resistance is "R". Then Ohm's Law comes into effect and A = V/R. So Neil's advice of plating at 1 to 2 volts seems easy to implement regardless of rectifier type.

What might be useful here would be to start at the beginning with something like: "I've been successfully electroforming with this solution for many years, then I added the 5 ml of brightener ..." or "I am just trying to learn electroplating, and haven't yet successfully electroformed my first piece ..."

Are you sure the air agitation was off when you plated the quarter? Stripes and ridges that occur with air agitation regardless of current density indicates a shortage of a certain brightener according to the "The Canning Handbook" style= [link is to info about book at Amazon].

Luck and Regards,

pic of Ted Mooney
Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

October 22, 2016

Q. I would like to make Electroform for hollow charm , Please let me know what kind of wax I can use and how to takeout the wax.

Quang Ha
- Atlantic City NJ-USA

Copper Electroforming Troubleshooting

December 17, 2016

Q. Hi there,

First off- thanks so much to all the folks here who are so dedicated to sharing their wisdom; I've been lurking around this forum for a while and have really appreciated the knowledge that's shared so freely.

So -- I've been reading up on electroforming for the last year and finally got a power supply and the safer solutions, paint, and started giving it a go. I immediately ran into trouble, and as I've been searching this forum and the web haven't found some of the information I'm looking for.

Here's my basic set up. I seem to find this recipe everywhere -- 1 gallon of distilled water, 32 oz pure copper sulfate pentahydrate, 120 ml sulfuric acid (battery acid) and 10 ml brightener. Some recipes call for HCl as well which I have but did not add.

I tried initially to paint a starfish coated with the Safer Solutions paint. I started with a 6 V battery,and got some rough, crackly looking plating at the edges (cathode was wound around center of the starfish).

I switched to a DC power supply and got the same effect.

Testing the resistance of the solution I belieive it was 300 ohms, so it should be working, but when I turn on the power supply I can get it to .07 of a volt, max, and no current. Just testing some rods in the solution connected to anode and cathode I get no current flow.

(solution is heated with an aquarium header to 80 °F and agitation with an aquarium pump)

On my second attempt I used a piece of steel so I could be sure what was happening (with the copper paint it's really hard to tell what's plating and what's paint)

Now just placing the steel in the bath it immediately plates, even without any current flowing, and the plating immediately flakes off.

I'm assuming either the recipe is wrong, or the pH has changed due to my previous attempt. While I did coat the starfish completely, I thought, perhaps some open crevices allowed contact with the solution and some was dissolved.

I'm not sure what problem is going on with the current not flowing ... the power supply is used regularly by multiple people and doesn't seem to have any problems.

So the questions:

Where to start with troubleshooting this?
What are some standard recipes?
What pH should my solution be? (I'm going to purchase a tester)
When testing a piece, after pulling it out, a green patina develops quickly, is it terrible to put that back in the bath? If so what should I clean it off with? (especially with a rough, organic shape, polishing doesn't work)
What kind of current flow would I expect with the proper electrolyte solution? Or what kind of resistance?

I'm doing this as a hobby, mostly to make pretty things for myself or as gifts for friends. I also make big steel art and am working on some pieces that I would love to incorporate interesting copper forms into.

Thanks so much for your advice and pointing me in the right directions.


Cjay R
Hobbyist/ artist - San Francisco California, USA

p.s. I already discovered that the steel will plate simply from an immersion in the bath, so that mystery is solved. It's hard to test how the copper is plating onto a surface with copper color.

December 26, 2016

Q. Dear ALL especially Ted

Merry Christmas and Happy Hannukkah and Holidays to all of you.

For the website/platform, this sharing of knowledge and information is really amazing!

I'm an art fabricator - realising sculptures for artists. Over the last 8 years I developed a workshop in electroforming. Being educated as a foundry technician in an art-foundry I worked with many techniques and metals before I started this quite large "experiment". But sometimes I realise that I miss a basic education in the field of plating. As well all the books I have give answers, but often to specific problems - just some wage hints.

085-1a  085-1b  085-1c  085-1d  085-1e  085-1f

This is the setup we work with:
We have view acid sour copper tubs, from small to bigger scale (1100gallons). The largest piece we made in one piece was 7.3 by 6.2 ft. (230cm x 190 cm)
Most of the works we did by now where canvas like objects, 4 x 4 ft times 1.5 inches deep. We silver the the surface of the rubber moulds to make them conducting.

We use Enthone additives, work with filters the electrolyte is thermo controlled around 82 °F. Our normal deposit is around 0.08 inches of copper, forming with about 350A. We normally working with about 20 A/feet2 (2A/dm2)

Now we do have some problems and some things we never really found the answers for. Therefore I'd like to try to get some answers here.

1. we used to have more or less tension-free copper. Lately we experience our electroformed "panels" to have a concave or convex "stomach". As there would be too much surface material. We made several tests with straight flat objects like glass. The copper on the "mould" it looks fine and straight, when we de-mould the copper, it bends.
We didn't always experience that. The analysis are fine (content of copper, sulphuric acid, chloride and additives)
Does someone knows this problem? or maybe a solution for it?

2. we have sharp 90 degrees angles in the mould (the edge of the panels) and by nature the edges are very thin and weak. Even more the corners.
Is plating with lower or higher currents better for this edges? Or would an alternating rectifier create a more even deposit in the edges and corners?

3. welding of electroformed copper is almost impossible (as I understand because of the hydrogen in the structure) is there a treatment to solve this problem?

thank you very much for your time!

Jan Eugster
- Saint Gallen, Switzerland

Can I use ANY epoxy?

January 4, 2017

Q. Hi I am just starting out in electroforming and am in the process of buying the necessary equipment etc. I obviously want to buy the best supplies but also don't want to pay a ridiculous amount unnecessarily. So can I use any epoxy or does it need to be a specific type?

Tanya Nicholson
Jewellery Designer - Southampton, UK

January 6, 2017

Q. Hi my name is Ronnie I have been trying to set up my own copper electroforming solution. I have been buying ready-made solution online and want to switch over to homemade. I have all the material I was just wondering what my pH has to be? I read the thread but could not find any info on it. Also I am looking for anode bags would anyone know where to get some ?

Ronnie ramirez
- Oxnard, California, united states

January 2017

A. Hi Ronnie. Although the suggested pH of nearly every plating solution is listed in the textbooks, I went through at least 6 or 7 of the best known texts searching for the pH of acid copper sulphate baths and came up empty. My conclusion is that the pH value must be considered distracting and non-useful. Control the sulphuric acid ratio rather than the pH.

Please use Google or a directory for vendors of "anode bags"; we don't suggest vendors in this forum for many reasons including the fact that the lure of free advertising is irresistible. Good luck.


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Teds signature
Ted Mooney, P.E. RET
Pine Beach, New Jersey

January 7, 2017

Q. Hello, I have a few questions.
1) How do you correct your copper solution if you have an organic contamination?
2) Also, how do you know when the pH level needs to be changed and how do you do so?
3) I use graphite paint and Midas copper electroforming solution. I've used this on silver, brass, copper etc.
I've seen silver conductive paint and solutions and it's way more expensive. At what point do you use those? Am I not supposed to use the graphite paint and solution on metals other than copper?
Thank you!

Zoey Kemp
- Kona, Hawaii, USA

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