DIY gold plating, anyone with experience? - Page 1
Forum section: electronics / general

author: aronake
author_rank: Frequent Contributor
timestamp: May 31, 2025, 04:43:58 am
content: I mostly use pure copper spades for low EMF. They tend to oxidize quite quick so more and more using gold plate versions. The gold layer on these tend to be quite thin and war out, and there are cases when I want some connecter where its possible to get pure copper, but the supposed gold plated version can be of dubious gold plating, suspected brass underneath etc.Do anyone have experience DIY gold plating with electrolysis? Something like what is described here:https://www.wikihow.com/Gold-PlateAny experiences anyone have to share? How was result? What process used? Recommendations on how to treat copper before gold plating it? Which gold plating liquid did you buy? etc.

author: coppercone2
author_rank: Super Contributor
timestamp: May 31, 2025, 04:48:41 am
content: it does not work on copper correctly because you need a barrier layer. At that point its not very ideal and you get into contented territory. Gold does solid state diffusion into pure copper.I was thinking about this alot for the DIY stuff and I realize that like covers (i.e. silicone) and deoxit is better bet then trying to figure this outat that point you have a unstable composition of intermetallics that grows over time if you use gold. If you use nickel plating first then its by the book correct metalurgy but then you need to be sure about what the nickel does. (and that is if your nickel is good, no cracks, etc)And most connector gold is not pure gold its hard gold meaning its an alloy of gold and something else (usually nickel)whatever metrology connector manufacturers do is well tested and it has a consequence (which they evaluate to be within the limits of the system that its supposed to be in) but its not optimal for the signal

author: Overspeed
author_rank: Frequent Contributor
timestamp: May 31, 2025, 06:07:57 am
content: Hellogold plating by electrolysis produce a porous surface , that very difficult to generate a 100% covered surface so you will have corrosion with time but also flatness problems at the contact level , best solution is to use PVD coating as Rolex watch maker usehttps://www.bendplating.com/gold-pvd-coating/PVD coating allow also to use ternary alloy base on Gold and Palladium to improve wear property AgPd30Cu5 is used for slidding contact because that one of the hardest alloy base on Gold .Best easier cheaper solution is to use silver plating , need some coins or old silver spoon , some nitric acid to produce AgNO3 , and time to tune the process but as that cheap no money lost in infernal Gold price . And the advantage if you tarnish /wear .... you can repair easy by removing the silver plating and make a new fresh one .RegardsOS

author: coppercone2
author_rank: Super Contributor
timestamp: May 31, 2025, 06:17:26 am
content: I don't think it matters how you put the gold on, it still diffuses into the copper, regardless if its PVD or electroplating. Watches use generally strong materials and don't care about electrical conductivity.Then the other consideration is that this is metrology, and that most connectors don't care about the property that you are seeking for low voltage behavior with noise or drift or offset.I think there is a whole slew of technologies and none of them are really 'optimized' for metrology purposes, though I think there is a wide area of regions where it will work fine for less digits or less stable instruments and stuff like that. I seem to read about alot of people getting really mad with nanovolt meters / 8.5 digit meters and basically say "use bare oxygen free clean copper wire, or else' (along with the other side of people getting irate over triboelectric noise in electrometer leads)Also something I noticed : most electroplating formulas have two or more catagories of formulasyou optimize for1a) looking good (jewelry and expenisve consumer products boutique)1b) being really fast for mass production and looking good. this is why your cheap shower faucets totally fail in a year2a) engineering (i.e. expenisve chrome plating job for expenisve bulldozer hydraulic cylinder, something with $$$$ engine, etc)2b) being really fast for manufacturing because of quantity with significant compromises for engineering even if its engineering. Like sour dough vs instant bread (crimp on belt fed folder connectors that are plated on the assembly line in a conveyor belt, from a real brand (cheap no name connector might fall under the umbra of 1b)Most of the kits you get are for #1. One of the corner stones of the entire industry is "ooohh shiny" . Engineering nickel looks like shit compared to "looking good" nickelif you compare cheap and expenisve connectors (i.e. battery cavity of the same design) do a bend test. I found the $10 version of the battery holder from digikey took 5 bends to snap the pin. The $2.5 identical looking version from china broke in 2 bends, I believe because of stress from the wrong nickel plating used that looked great but had incredible strain on it., Sure would not want that to happen near 18650's

author: Overspeed
author_rank: Frequent Contributor
timestamp: May 31, 2025, 06:33:06 am
content: Helloit still diffuses into the copperhow that possible as that platingPVD gold coating is used in marine application and aerospace application to avoid corrosion ( water level sensor and other sensor with atmospheric contact ) as electroplating is porous or extremly difficult to reach at 100 % level covering with a proven quality control except if you spend a lot of time time and money to TEM / SEM inspection or destructive testing .Another good solution cheaper than gold is PVD coating with Ag Pd alloy as Palladium is cheaper that Gold and as Silver is complety soluble in Palladium , not include that produce a wonderfull surface color .High level watch maker want and search a perfect result with no Quality concern , that perhaps not electronic but the process is proven .DIY PVD coating is not rocket science if parts are small , some YouTube video as Applied Science shall be watched .RegardsOS

author: coppercone2
author_rank: Super Contributor
timestamp: May 31, 2025, 06:34:48 am
content: direct PVD gold on electrical copper is used?They always say it has a nickel under coat. They call it a flash layer. For most anything electronic. I understand it like putting a non permeable liner under your swimming pool before you put tiles.Maybe BeCu has some resistance to gold diffusion because its super hard in comparison, but I don't know. But you would not make metrology lugs from it.and I thought most marine stuff iscupro nickel. like money. or monel.Those sensors you say are very high impedance AC and don't exactly measure a stable parameter. Why would they use copper for a water level sensor?? We used stainless pins. I don't think gold will diffuse into stainless, if you wanted to gold plate it. Same for crude conductivity sensors (good ones need the glass electrodes)Something about pure copper makes it wick up stuff. Like oxygen too when its hot it will absorb oxygen really good.as always check I had a co worker told me they were made to put solder pot tinned wires into screw terminals for helicopter systems (because its faster then ferrule)! I don't trust big companies

author: Overspeed
author_rank: Frequent Contributor
timestamp: May 31, 2025, 06:49:01 am
content: HelloYes for some aerospace sensors as corrosion with sea water is a real concern as electro gold palting is just a name but a extremely difficult process to certify at 100%.PVD is also a cheaper process and quickerRegardsOS

author: coppercone2
author_rank: Super Contributor
timestamp: May 31, 2025, 06:54:50 am
content: I am asking if they use direct PVD 24k gold on OFE copper (C10100 or even C11000).

author: Overspeed
author_rank: Frequent Contributor
timestamp: May 31, 2025, 07:57:30 am
content: HelloYes on copper and mostly all other metal and alloy even some plastic , PVD is very popular process , BUT PVD need also Quality control , some chinese quick and cheap PVD are just .... crap.In industry the unit is % , sputtering target ( the PVD material source ) are available in 99.99% as usual product or 99.999 % but that a crazy price .If I shall go to PVD for lab use without any marine / sea water problem I will go to Ag Pd alloy which is more durable than soft GoldRegarding sensor design that not my concern I have just run validation test when there is Quality problems , a aerospace with anairworthiness tag is under the supllier liability for the design , Gold plating is also use to prevent fouling on parts whatever is the base material .RegardsOS

author: coppercone2
author_rank: Super Contributor
timestamp: May 31, 2025, 08:08:46 am
content: I wonder why thats OK, tons of sources give a pretty clear NO for gold on copper. I have been hearing a NO for gold on copper for for electronics for like 15 years since I was remotely interested in the process.

author: aronake
author_rank: Frequent Contributor
timestamp: May 31, 2025, 08:16:03 am
content: Thanks for very good input! Apparently we have some gold plating experts here!!

author: coppercone2
author_rank: Super Contributor
timestamp: May 31, 2025, 08:20:19 am
content: Also do the math to figure out how much gold you need it might just make you decide to stick with a polishing cloth.The thickness * the surface areait gets ugly quick. check out how much gold is in those solutions as depositable too. for the price.It made me say HELL NO. Its 19.3 grams per cm 3 and you will find that any gold plating iswayabove market price for gold metal.the PVD is actually appealing for that reason aloneseriously the price is preposterousI did the math for a few objects I thought would be cool to have to be gold plated (for RF things) and I just totally killed the idea when I see what it looks like for that nice "thick" gold plating that they say you should have. Last year I spent like 3 weeks reading about all the solutions that I can get and the options and quality and how to do it exactly, wrote a plan, then I did the math with the surface area and threw it all out after I did the math to figure out how much I can get out of the solution and did the price math.wipe tears away with thishttps://www.blitzinc.com/products/blitz-copper-shine-copper-polishing-cloth

author: Overspeed
author_rank: Frequent Contributor
timestamp: May 31, 2025, 08:27:13 am
content: HelloI just try to explain Gold on Copper is perhaps not the miracle solution as :Gold is weak regarding wear so you have the concern of : maximum mating cycles except if you reject them after a fixed number of cycleGold need to have a reliable thickness AND uniformity to avoid galling / fretting ( quality check / control )There is other alloys ( check Mattey company ) for contact alloy designed for this purposeRegarding the long list of concern I coat mostly nothing I clean the coppy parts by using a quick electropolishing + solvant drying and store them in a dry place ( plastic drum with dissicant )PVD is used for :thickness uniformity100 % coveragequick processNo dangerous chemical needSurface roughness after coatingall surface covered without tricky electrodes concernsAble to coat mostly any metal on any metal without the need of complex chemicalsAble to coat small parts without current level concern or parts strainPVD is a real improvement and not at all a chinese cheap process from Aliba... even if now there is a lot of high quality chinese product which are fully respectable .PVD can be DIY in your garage with a minimum of investment except the sputtering target costRegardsOS

author: coppercone2
author_rank: Super Contributor
timestamp: May 31, 2025, 08:47:59 am
content: do you got a pics, vid, etc of a PVD machine someone built that looks usable for real (electronic) parts to you as someone that knows about this process actually being used?I have seen some 'experiments' that look like they can put some metal on some simple thing like a flat substrate but I am not convinced it would work for say coating a crimp.

author: coppercone2
author_rank: Super Contributor
timestamp: May 31, 2025, 08:55:50 am
content: for instance what is the name of the clamp that holds the evaporation boat (complex copper structure) ? I wanted to see priceOr its something that needs to be made ?

author: Overspeed
author_rank: Frequent Contributor
timestamp: May 31, 2025, 08:57:07 am
content: HelloSome video on YouTubeApplied science have a lot of detailled video on PVDbest is to start with Silver as that cheap and a silver coin can be used as sputtering targetRegardsOS

author: coppercone2
author_rank: Super Contributor
timestamp: May 31, 2025, 09:04:11 am
content: Do you know what this part that holds the boat is called? and a distributor or generally good design for that part?High current vacuum feedthrough with interconnect"boat holder" or "boat clamp" or something like thatis there a more proper name?https://www.laddresearch.com/vacuum-equipment/digital-high-vacuum-system-accessories/boat-holder-accessories/boat-holderbut TBH I like chemistry and i don't like vacuum systems.ever notice how there is always alot of crinkly aluminum foil all over vacuum laboratories? I hate that. way to class up the jointI doubt I will ever do this. It will end with a big heavy stainless steel flange pipe sticking out of something under the table covered with sandwich armorI am very excited to try nickel sulfamate and iron chloride plating soon. TBH for silver, Kool-amp rub-on powder is good enough for me. Its not very durable but it takes like a minute to restore any problems. I used it to cover a heat exchanger I made for cooling water for the kitchen because the refrigerator ice machine was getting frozen from over use when blanching,and it hold up pretty well over a year. A little tarnished but its actually pretty great. And its pretty easy/safe.

author: coppercone2
author_rank: Super Contributor
timestamp: May 31, 2025, 09:45:55 am
content: when you complain about the copper tarnish and you figure out the price of goldhttps://imgur.com/gallery/doh-QQ7TkMC

author: Overspeed
author_rank: Frequent Contributor
timestamp: May 31, 2025, 10:10:39 am
content: HelloIn metal plating , the word shinny is banned , you can spend years to try to compete with PVD coating that just a lost of time and money for a poor result .Only conventional plating I run is silver plating of PCB as that not a friction concern but a soldering / corrosion concernRegardsOS

author: dietert1
author_rank: Super Contributor
timestamp: May 31, 2025, 01:38:53 pm
content: I remember some electroplating together with my wife to protect brass parts (reduce cleaning efforts). We ordered a kit from ebay. It was easy yet slow and we had a good result. Those parts are still shiny after more than 20 years. Considering the low entry price of € 60 or so for a small bottle of electroplating liquid i think it's worth a try. Gold plated copper parts will certainly last a lot better and you can always repeat the procedure.Regards, Dieter

author: Overspeed
author_rank: Frequent Contributor
timestamp: May 31, 2025, 01:54:31 pm
content: Quote from: dietert1 on May 31, 2025, 01:38:53 pmHelloThe first problem is linked to the purpose of the plating:IF that for static contacts as edge contact on PCB so little to very little connection / deconnection so a little level of wear , fretting is a concern if you are an environnement with vibration as automotive parts .ORIF that for testing purpose so daily connection / deconnection , gold plating need to be thick and whith a near perfect or other plating shall be used , all manufacturers provide the number of mating / contact life , 500 is a common value .RegardsOS

author: dietert1
author_rank: Super Contributor
timestamp: May 31, 2025, 03:18:52 pm
content: I also remember how to remove copper oxide with household "chemicals". I used a glass of vinegar and inserted some tea spoons of salt. Once the salt is in saturated solution you can insert your copper parts and they will be shiny the next day. Don't forget to recover the parts as they will be destroyed otherwise. Guess how i know..Once the parts are shiny, you can electroplate them.Regards, Dieter

author: Overspeed
author_rank: Frequent Contributor
timestamp: May 31, 2025, 04:11:08 pm
content: Quote from: dietert1 on May 31, 2025, 03:18:52 pmHelloRegarding the de-oxyding by using acid , you shall in consideration that etching the surface don t improve the surface roughness but make it worth , not massive degration but .... that why I use electropolishing that fast ( few minutes) safe if you control current level and that improve the surface quality by removing high spot at the surface roughnee scale) .A crucial parameter when you use any acid bath is to perfectly neutralize the acid with distilled water ( at least two baths ) and just after dry it FAST with acetone or cholorform as very fast evaporation solvant to avoid any new oxydation.RegardsOS

author: helius
author_rank: Super Contributor
timestamp: May 31, 2025, 04:47:55 pm
content: If any kind of durability is desired, a heavy layer of nickel electroplate must be used prior to gold plating. This is not "flash", it's the thickest part of the surface treatment (twice as thick as the gold surface plating). Hard gold used in electronics is an almost pure gold alloy, with very minor impurities usually cobalt or iron at 0.5% or so. The hardness is from the crystal strain caused by the alloying elements, not their bulk properties. Hard gold solution is more expensive than even 24 k gold solution.To protect metal from rust or tarnish requires more than simply drying it. Oxygen and moisture are in the air itself, so the chemical reaction of corrosion can happen even if the metal is dry. What protects most metals most of the time is their native oxide, which in the case of e.g. aluminum, forms fast and is very strong. After the native oxide has been removed, there is a period where the activated metal is especially sensitive to corrosion and should be protected by covering it with a barrier to slow the contact with oxygen. Oil and wax are effective barriers. Once the native oxide is re-formed, the metal is less vulnerable.

author: coppercone2
author_rank: Super Contributor
timestamp: June 01, 2025, 04:16:32 am
content: what about the internal stress in these pvd coatings?I can't find many numbers but the MPa looks rather highidk if sulfamate nickel is appropriate for connectors, but the internal stress on that is something like 50. Some numbers online for PVD nickel is 650.IDK if that is a problem for a lug but for a spring type....

author: Overspeed
author_rank: Frequent Contributor
timestamp: June 01, 2025, 07:01:42 am
content: Quote from: coppercone2 on June 01, 2025, 04:16:32 amHelloOriginal was how to make gold plating easy ...If you want to investigate in internal stress that request X ray equipements or at least curvature test sample if you DIY that the same idea as ALMEN test samples in use for bead blasting shot peening .But on copper spade and other lab connectors as plugs I do nothing as I have only one life and other thing to do.RegardsOS

author: Overspeed
author_rank: Frequent Contributor
timestamp: June 01, 2025, 07:13:46 am
content: Quote from: helius on May 31, 2025, 04:47:55 pmHelloHard Gold is not ENIG as Hard Gold is mostly be able to be soldered , Cobalt and Iron are alloy elements to increase hardness .Native oxydation is a real problem and that shall be taken in consideration for accurate measurement because that not visible ( green tarnish on copper ) that why parts shall isolated from air and water . Storage in Argon flushed container is a solution or vaccum bag as meat and food storage bag .RegardsOS

author: coppercone2
author_rank: Super Contributor
timestamp: June 01, 2025, 07:29:21 am
content: strain is a little scary because I saw things snap or crack in half before. I once saw a crimped ring terminal that cracked between the wire barrel and the ring part. (green line). I wonder why it broke there of all places. and it was connected to a loose wire with plenty of slack in a race way. It remind me of how glass breaks, its just sitting there and crack. This was for a transistor in a DC volts calibrator. From the stickers left behind it looks like it was fine with passing cal every year for maybe 20 years... until it broke and someone put it on ebay

author: Overspeed
author_rank: Frequent Contributor
timestamp: June 01, 2025, 12:11:31 pm
content: Quote from: coppercone2 on June 01, 2025, 07:29:21 amCopper as anneal state used on crimped parts is a higly ductile material I strongly doubt a strain during the process can cause major failureRegardsOS

author: coppercone2
author_rank: Super Contributor
timestamp: June 01, 2025, 09:18:45 pm
content: I think they make it a little harder (copper alloy) but its still very weird. IIRC it might have been a nickel coating because the crimp was VERY shiny (when I take things apart sometimes I do a tiny bit of hand polishing on flat crimps if they are tarnished, along with a touch of electronics grease) and I was pleasantly surprised with the surface condition.Nickel CAN end up very stressed according to electroplating tables. I thought the location where the crimp broke is rather unusual. That part is like the strongest area, I think its weakest right at the barrel. I associate this asinine behavior with glass. Glass seems to break in unusual areas sometimes. Metal usually not.And BTW it was like a 20 AWG wire too and the crimp thickness was the usual for a ring (not super thin)

author: Overspeed
author_rank: Frequent Contributor
timestamp: June 02, 2025, 02:22:06 pm
content: HelloCopper as all copper are not equal as the draw hardness is a crucial parameter from full anneal to 4/4 hard that right from plumbing pipe up to electrical wire and also machining barIf your copper are thin AND hardened by lamination process you can get crack in the raw material .Same for SS steel 301 hard is used a spring steel but 301 anneal is soft as '' butter ''RegardsOS

author: coppercone2
author_rank: Super Contributor
timestamp: June 03, 2025, 12:01:07 am
content: I don't know how the crimps are made, but you would think it would have been high quality for a voltage/current calibrator (possible company name 'digitech' and related to 'data precision'), never found any info on it, however I don't care because the HP multifunction synth can do DC with fine DAC steps and the hp current source can do current with fine potentiometer, and i only ever used it as a low current source for voltage and current for circuits