Gold flash vs. plate

A. Hi Lori. That's beautiful old stuff you've got there. I'd guess you probably need underlayers of copper (mush buffed to restore smoothness), nickel for brightness and as a diffusion barrier, gold (probably about 1/4 to a 1/2 micron, but a full micron wouldn't hurt except for doubling the price of the gold), and a clear coat for durability (gold is inert, so strictly speaking clear coating is not necessary, but using gold as a wear surface when it will be scrubbed is probably impractical).

Still, trying to write your/our own specs for a one-off job may not work to get you a quality job. I'd suggest trying your best to find a shop with experience in very similar stuff. I'm not sure who can quote on this, but in the NYC area I'd suggest talking to Epner Technology in Brooklyn and SA Baxter on Lexington Ave. Even if they can't quote they almost surely have experience in referring people to someone who can.

Luck & Regards,

A. Those terms are meaningless.

A. In electronics plating these terms are not recognized.

In the jewelry industry there are distinctions for "flash", gold plate and heavy gold electroplate.
"Flash" refers to thicknesses less than 7 millionths; gold plate, above 7 millionths; and heavy gold electroplate, 100 millionths of an inch. All measurements are expressed in terms of 24 karat gold.

A. G'day, The term flash means to just cover the job with enough gold to give it a uniform color. Usually a cyanide gold. The term plating is short for electroplating. Connectors have varied uses. Some require more gold than others. Most mobile phone connectors have a thickness of 1.25 microns near the tip. Most connectors are electroplated in an acid hard gold first. This gold is an alloy and offers better mechanical wear protection. Then a flash of 24 kt cyanide gold to give it an even color.

A. Flash gold plating is less than 0.25 Microns and usually not done on connectors. For this purpose, Cobalt or Nickel hardened additives are used in the Acid gold bath and usually a thickness of >1.0 Micron gold is deposited and is subjected to tests such as contact resistance, wear resistance, porosity etc.
In this case Mr. Bruce J has to set his requirement first.

A. Bruce:MIL-DTL-45204, Paragraph 6.3.1 defines a strike/flash as any plated material under 10 micro-inches or .000010. Depending on your application, we see 30 micro-inches of gold commonly on commercial connector applications. Mil-specs such as 39029 are 50 micro-inches min but also allow localized finishing. We routinely process size 16-22 gauge pc tail contacts and sockets with copper flash, nickel 50 min, gold flash/strike overall then selective plating mating end of socket or contact.

A. Hi Bruce. A parallel if I may: in English grammar class we learn the distinction between words like "which" and "that" -- when & why we ought to use the one rather than the other. If your desire were merely to try to use the word "flash" vs. "plate" in 'grammatically correct' fashion in a particular industry segment, you've just heard 5 good explanations.

But I think the central point is that trying to specify the thickness of gold plating by calling it a flash, or trying to determine what someone if offering you by the fact that they called it a flash, will prove hopeless. Thickness must be specified, not inferred from the word "flash". Good luck.

Luck & Regards,

A. Hi Steve. This situation is even worse than the previous questions about gold "flash" because now we've introduced a second vague slang-y term, "micron plating" :-)

To some people "micron plating" means gold plating to a thickness of approximately 1 micron thickness (i.e., 40 millionths of an inch) for gold plated sterling jewelry or other high quality costume jewelry. So this thickness is probably significantly greater than a flash plating, which might be more like 7 or 10 millionths of an inch. And I have only heard the term micron plating used for gold plating, not plating of other metals.

But again, the words "flash" and "micron plating" should probably only be interpreted as grammatical constructions, not used to imply or infer plating thickness.

Yes, in general, you can easily deposit either 7 millionths or 40 millionths from the same gold plating bath with the same machine, although there may possibly be some "color golds" that might not do well except within tight thickness parameters. Good luck.

Regards,

A. Hi Martin. There is no "normal" thickness I'm afraid :-(

Just for a sense of things, the plating on most cheap costume jewelry is significantly less than 1 micron. I believe that the slang term "micron plating" originated in an effort to distinguish mid-quality costume jewelry from junk: sterling silver with about 1 micron of gold plating, the quality a college guy might give his steady date.

Very good costume jewelry, "vermeil", is your 2-3 microns (although I think vermeil requires that the substrate be sterling silver rather than stainless). I understand that super premium watches have about 7 micron thick gold plating. Century old pocket watches might have had 20 microns, so I think it unlikely anyone would want more than 20 microns for jewelry.

Luck & Regards,

A. Hi Martin,

50 microns of gold is certainly possible, even thicker coatings can be obtained. The platers in China are correct though, that is going to be very expensive.

Thickness is dependent on what you want it to do, but a thick coating for jewellery chain is more like 5 microns rather than 20 microns.

A. Normally I am used to have open calculations when talking gold plating, but I would certainly check if 50 microns actually was applied.

A. I will agree with the other respondents and say 50 microns of gold is very possible. I once worked for a company that plated more than 127 microns of gold on electrical contacts. One thing I will tell you is that it will not be shiny gold when you are done. Also when plating those thicknesses of gold the bath has the strange and inexplicable ability to keep drawing current while the metal deposition stops completely. We never figured out how this was done. We just knew that every 5 microns or so (.0002") we would have to pull the rack and run it through an acid reactivation cycle and then continue plating. A real pain in the derriere.

A. Hi Jayson,

You really need to give us a lot more detail about what you are using the gold for, rather than asking an abstract question. All I can tell you at the moment is that your gold will be 20 microns thinner!