Metal plating plastic or metal parts | Hacker Day

2021-11-12 09:34:32 By : Mr. Frank Zhang

Like most of us, [Clem] wants to use metal for 3D printing. Metal 3D printers do exist, but for most of our garage hackers, they are usually out of reach. As an alternative, [Clem] uses a self-made electroplating system to obtain prints with metal coatings.

The setup is very simple. Used as a small glass tank for the electroplating tank, the machine uses an Arduino controller and PCB to fix things like relays to control the 24V used for electroplating. To keep everything tidy, [Clem] designed a 3D printed box that can store all cables and chemicals when you are not using them. Since the parts may become hot, the plastic is PETG.

The trick is that parts need to be conductive to use electroplating-usually plastics do not conduct electricity. [Clem] Paint plastic parts to give them conductivity. Graphite paint did not give good results. However, iron-based coatings are better, but they will obscure the details of the printed matter. In addition to galvanizing (galvanized or steel-plated), you can also see the copper plating of the nail at the mark of about 12 minutes, and a demonstration of the plastic coating will take place one minute later. The machine can even use expensive gold-containing electrolyte for gold plating. In the video comments, it was also mentioned that it would be interesting to try to electroplate the conductive wire without using paint. [Clem] tried to remove the rust on most parts, but the power supply could not complete the task.

Copper plating is usually used as a step to make parts conductive, so you can use another metal for electroplating. In addition to copper sulfate, you can also use copper acetate. Sometimes, it can be difficult to make metal into fine details, and it is easier to electroplate these areas directly with a pen.

Nice small device, another upgrade to this might also be a method of reversing the polarity during the plating cycle in a very short time. Generally, if you are building a thick plating layer (electroforming), you can switch the polarity for a few milliseconds after laying the base layer to get the meter surface.

Take a fish tank, put a metal plate as the base material, fill the fish tank with copper sulfate solution, put a condom or other cheap flexible waterproof material on the robot arm, and add a sharp copper rod as the end effector to make it Fix it to an adjustable arc welder or 40A desktop PSU as an electrolysis power source, and then print it out until you are satisfied. Possible improvements may include replacing the robot arm with a real 3D printer and replacing the filament with a thin copper wire, if a suitable insulation method can be found before the copper wire reaches the extrusion head. Perhaps it is an oil-filled Bowden cable design that pumps oil into the cable and then recirculates through the pump when the oil floats to the surface. If the stepper motors of a 3D printer are potted or replaced with a gear brushless design and encoders are installed, they may be submerged. Alternatively, a larger oil layer can be introduced, and the copper sulfate solution can be just a thin layer at the bottom, just enough to cover the print head and the workpiece. In this way, the electronic equipment will always be in the oil. As the printing night increases, new copper sulfate solution can be pumped under the oil layer. Maybe you can use something like a cheap car windshield washer pump, because the flow rate does not need to be too high. Please note that for larger projects, printing will undoubtedly take a while.

Why waste people's time? ? He never said that his magic power supply is different from a simple workbench power supply. He did not discuss the actual chemical reaction. Is he a chemist? What about cleaners, levelers and brighteners, as well as temperature and pH control, and all other necessary details of electroplating? How to dispose of chemicals responsibly? The entire industry is dedicated to electroplating. Although there are some trivial amateur videos that show concepts suitable for high school science classes rather than industrial processes, it is not simple. Having played with these things for decades, I can say that amateur coatings are generally not smooth and shiny, cannot adhere properly, peel off easily, and there are many other problems. There are several companies that sell most of the effective proprietary chemicals, even though it is toxic and expensive. Why is there no kit for through-hole plating using D batteries and some vinegar? Because it doesn't work. Of course, expensive kits require a lot of effort. Etch the circuit board? simple. Anodizing is usually easy. Electroless tin plating is mainly effective and quite cheap. Silver displacement plating is mostly effective, but it is expensive and rarely used. Practical copper and nickel plating, forget it.

Thank you for providing keywords for further Google searches on the subject. As always, comments are more valuable than half-sent "articles" based on YT videos.

I would also add that because silver nitrate is toxic, it is very difficult to obtain it in different EU countries.

There are always people like you in the comment area, right?

Instead of addressing the merits of the content, you immediately use your "expert" opinions and belittle the content because you "know better." Articles like this—although they do not detail industrial-scale applications...because they do not need—provide people with a process they might not know about. There are many people who print miniatures or figurines, or are looking for a way to add a little style to personalized gifts...I believe they will be very interested in using this video and article as a starting point. In other words, a place to start.

Next time, instead of complaining about the content, why not leave it to yourself?

Because real plating is difficult. It makes no sense to go around in circles on this issue. If someone is unlikely to succeed, then I would agree with you, but that is not the case.

You will find a lot of this "can't do" attitude on the Internet. The emerging electroplating forums are either directly operated by the electroplating industry trolls, or they are taken over by the electroplating industry trolls to scare people not to try, but to push their business to themselves.

It seems to be a cutting-throat industry with a lot of trade secrets and a very valuable regulatory barrier to entry. A company troll threatened to report me to the EPA, suggesting to pour a pint of root liquid into the sewer, which is the purpose of the clear sale. (And you used one-twentieth of the "single dose" container in a pint of plating solution)

I hope to see more of this content on Hackaday, but I doubt it will attract corporate trolls, and you won't have any easier time. However, contrary to negative information, there are few sources of positive information on the subject.

I know that there are hazardous chemicals in certain electroplating processes, and people should probably consider putting them at home carefully. However, there are ways to explore less toxic alternatives, all of which are often rejected by "professionals." People can also produce toxic chemicals from seemingly harmless chemicals (beware of hexavalent chromium), so it is recommended to have a good understanding of chemicals.

A starting point is the older "receipt" public domain books, or as we say in modern cookbooks, if we are talking about food. Then you can unearth some patents, although as mentioned earlier, the business seems to involve more trade secrets. Some mentions can also be found in older hobby magazines in mechanics and science.

Finally, some simple things I collected from my electroplating adventure... i) This is not about volts, but about amperes. ii) Use distilled water. iii) Get any chemical cleaning materials you want to electroplate.

Here is some information about electroplating

I watched a considerable part of this video a few days ago, and finally closed the tab before the video was completed, because it was obvious that this was not a real HowTo, and my time was wasted.

As for making plastic parts conductive, several methods look promising. Electroless nickel plating is commonly used in industry, sputtering/CVD is always an option (although expensive and not suitable for complex parts), and silver mirror solution should be effective (Nile Red has an excellent video on the process: https:/ /www.

"Metal 3D printers do exist, but for most of our garage hackers, they are usually out of reach."

Isn't this exactly what HaD readers say "I will build that"? It is suitable for the early days of 3D printers.

There are filaments with high metal content for FDM printers that are specifically designed to be placed in a high-temperature oven later to burn off organic debris and sinter the metal particles together. Yes, the prints are reduced by about 1/3, yes, the furnace will not be cheap, yes, the smoke from it will be annoying...but once it is done, you will get a large piece of metal that you want shape.

Again, HAD just published a post about 3D printing with conductive filaments made from old VHS tapes:

There is another way to wrap metal-filled prints in gypsum, and then allow lower melting alloys to replace plastics in the kiln through capillary action. It is not completely lost wax/plastic casting, because the final result is not a uniform alloy, and the mold does not need to follow all the rules required for casting.

I was lucky to spray graphite on non-conductive materials. I remember that although I was using a lower voltage. Some things can be bad at higher voltages. I will have to try Andrew's suggestion of reversing the polarity occasionally. If I make it too thick, I will see the crystals develop instead of a smooth surface.

Jack, I have been electroforming various things in copper for many years. Bronze braided bird skulls, roses, etc. I should really clean up the workshop and make a complete instructable or something, because there seems to be a lot of people keen on it.

For the primer, buy some cheap fine graphite powder from your local hardware store. Things used to lubricate locks and bearings work well. Mix it with cheap acrylic (clear) paint and dilute with water. I tried various mixtures and this is the easiest to make up for. Paint it in a very thin layer. I often lay about 8 layers, and then use an electric meter to test whether the item is conductive.

You can also use the thicker, painful version to fill in some gaps and holes, but make sure you build up these layers, as thick layers tend to crack when they dry. Eventually I got a small spray gun and started using it to speed up the process.

At first I just used copper sulfate to dissolve the copper in hydrochloric acid, and then added a little hydrogen peroxide to speed up the process. Then a large copper plate was added as the anode () power cord.

I used a constant current source and set it to about 100/120ma at 12V, although I lowered it to 5V and found that the surface became thinner and harder. The item is connected to the (-) track and is flooded. You should see some bubbles start to form, but if they bubble, turn the current down.

There is one for calculating the size of the object, current consumption, and time to leave it in the bathtub, but I usually just look at the results.

Switching the polarity for a few milliseconds every few seconds seems to reduce the accumulation of crystals around the junction of the item and the (-) track.

For things like roses, time wise, each of me will put them on the plate for about 6 to 8 hours. Some are left overnight, but pay attention to the current and adjust it, because when the item ps is electroplated, it will also become more conductive.

Make sure that the surface area of ​​your anode is larger than the item you are weaving.

You will also accumulate sludge at the bottom of the tank. To solve this problem, I bought an old stocking, put the anode in it, and cleaned it up from time to time.

The process of weaving other metals is roughly the same. Nickel is a bit interesting, and some cane handles have been made in this way. Although I bought nickel braiding solution and some brighteners and some nickel anodes.

I also played a process called Flash Plaiting, which is usually done on steel. Start the current and immerse the steel in and out of the copper solution until it forms a thin layer. This layer adheres better to the steel. Once all covered by copper, you can proceed to the nickel braiding process.

Don't bother to plate aluminum-based things, aluminum is corroded faster than metal is deposited on the surface:(

What resistance readings do I usually get when using graphite paint? Is there an ideal ratio? Great information!

sugar. Ordinary old cane sugar in the electroplating bath will help smooth the copper. You will get shiny metal instead of moss. The need to periodically reverse the polarity indicates that your plating conditions are incorrect. Long needles, called dendrites, make the plated metal covered with moss, which may be caused by weak bath and high voltage. High current, "just enough" voltage to promote the development of electrochemistry, carefully control the pH value in the electroplating solution, and control the temperature. Even if all these factors are determined, this is still an uncertain process. BTW, ordinary copper wire is alloy; not pure metal. The alloy metal may not be well compatible with the chemical composition of the electroplating solution. If you find that your electroplating solution can be used for a period of time, then it will deteriorate, which is why the alloy metal poisons the mixture.

Thanks Greg, next time I make some copper, I may have to try it because I ran out of brightener. It makes sense, because I think the brightener I use contains hydrogen peroxide, sulfuric acid and glycerin. I suspect they use glycerin instead of sugar/sucrose

How about plasma spraying? I have seen small rocket nozzles—such as attitude control—spray titanium onto aluminum mandrels by plasma spraying, and then use sodium hydroxide to etch away the aluminum.

Worked in a metal cleaning and electroplating workshop in NASA for 24 years, and don't even try to electroplate through holes. Shipley and LDC sell to qualified companies, not to individuals, because these chemicals are toxic and cannot be washed away. Electroplating onto plastic requires electrostatic charge. The parts to be electroplated must be "free of water and oil" and dirt, and then electroplated with a copper tin solution, then the tin is stripped, leaving the charged parts, and then the copper sulfate "strike or flash" is plated thin, and then the accumulated copper solution is deposited To a useful thickness. The leveling solution reducing agent in the electroplating solution helps to maintain the gloss accumulation. Mechanical polishing determines the final gloss when nickel plating on copper, and then whatever else you want to plate. Gold and silver cyanide solutions are the best, as the silver will fall off over time. So, don't bother to try plating. There is a reason why the cost of re-chrome plating of car bumpers is so high. The EPA and the Ministry of Environmental Quality will lock you in. Good day, stay safe.

Instead of iron-based paint, why not spray a layer of fine glue directly on the plastic, then spray fine iron powder on the glue, wait for the iron to stick to the glue, knock off the excess and then electroplate it? I think you can get better coverage and a thinner coat in the corners and crevices.

Oh, a warning to those engaged in 3D printing and Electro weaving...

I used to store my chemicals in the same cabinet under the woven bath.

Never put your acetone near other things...

Acetone hydroperoxide acid is super dangerous!

I believe this is the reason why large amounts of liquids are banned on airplanes. Triacetone triperoxide is highly explosive.

You will end up with various organic peroxides (they are also unstable and sometimes explode), but TATP is unlikely to be in it, room temperature is a disadvantage, and inorganic acids.

I have conductive copper paint and it seems to work very well. I also found that silver polishing can be electrolessly plated on ordinary copper.

Look for vacuum metallization. It should be possible to make a DIY outfit for this. This is how they make those electroplated plastic parts you see in model kits and flashlight reflectors. Basically you need a vacuum chamber (such as a bell jar) and then evaporate a piece of foil deposited on a plastic object.

"For this project, I used Arduino Uno..."

(A picture of the box labeled Arduino Mega appears)

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