Do electroless zinc & electroless brass plating exist?

A. Hi Danny. I strongly doubt that it is possible or will be possible any time soon. But you could start with abandoned patent application US20040072011A1

Luck & Regards,

A. My guess would be that your customer is looking for zinc galvanizing, as this is the only commercial electroless zinc process I am aware of.

A. Mechanical plating is another "electroless" zinc process. Suitable for springs and similar components indeed.

A. While neither of those processes uses electricity to drive the deposition, it might be a stretch to call those processes "electroless zinc plating" :-)

There's also flame spraying (probably not appropriate), Sherardizing, dip-spin coating with zinc-rich material, etc. But the bottom line is probably that that spec is a non-starter and must be revised; trying to proceed from that bad description can't possibly lead anywhere good :-)

A. Hi, cousin Shailendra.

In general, the parts are alkaline cleaned, rinsed, electrocleaned, rinsed, acid activated, rinsed, zinc electroplated, rinsed, chromate conversion coated, rinsed, and top-coated. They are then sometimes waxed or lacquered.

Depending on the size of the hinges those steps could be executed in a barrel plating operation, but more likely a rack plating operation. There are several different broad classes of plating solutions that can be used including acid zinc plating (chloride, sulphate, ammonia, or mixed varieties), cyanide (high, low, or mid), and alkaline non-cyanide; the alkaline non-cyanide processes are growing in popularity, although they're usually proprietary.

But there are books of many hundreds of pages, just on zinc electroplating and whole aisles full of books on these topics in large libraries, plus people who have spent their entire careers doing nothing but zinc plating.

Similarly, there are whole books just on the design details of plating lines and people (like me) who spent their whole careers working on the details of such installations.

We're happy to answer any questions you have, but you can see that providing "complete details" in a forum response is an impossibility. The best way to zinc plate your hinges is usually to contract it out to a plating shop. If you want to do it in-house, finishing consultants can provide the guidance.

Yes, there are a half-dozen or more alternative zinc application technologies, and each is similarly complex but has jobbers and consultants available. Good luck!

Regards,

A. I have a method for electroless zinc coating; it deposits a thickness of about 30 micron in a few minutes. It is valid for deposition on steel and copper also, and most metal surfaces. You can control the structure of the deposit even bright or not. If you wish I can send you the bath composition and the procedure.
THANKS.

!! Dear sir,
Zinc can be plated on any active surface by electroless method using ionic liquid as electrolyte.
Zinc chloride is added to molten 1-ethyl-3-methyl imidazolium chloride in a ratio 2:1 and stir this mixture.
Zinc wire is immersed in this liquid for one week to absorb moisture in a glove box under argon gas or any inert atmosphere. After that, reducing agent is added to this liquid that is di-isobutyl aluminium hydride in concentration of one mole after dilution with toluene.
The liquid is ready now for electroless plating on metal substrate at room temperature for half an hour.

Q. Ahmad: Good day can you post the process of electroless zinc plating?

Ralph Valentine
- South Africa
August 7, 2022

Hi. I think he already did, but we'll alert Ahmad to your posting if his e-mail address from 8 years ago still works :-)

Luck & Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

Hi. Thanks, Ahmad!

Regards,

A. There is also a simple way to coat Copper, Nickel, Iron or all metals more electropositive than Zinc, and this is by using the Enhanced Immersion or Enhanced Displacement process where the metal that needs to be coated with zinc comes into contact with a metal more electronegative than Zinc, in this case Aluminum plate. The aluminum plate is placed in a container, the container is filled with a standard Zincate solution, then immediately after that the metal that is to be coated with zinc is submerged in the container and makes contact with the Aluminum plate. Leave the piece in the container for about 5 minutes for a good coating of zinc. the aluminum plate needs to be removed to stop the electrochemical process.

I need to make a video of that soon :-)

A. Hi Ralph. To my knowledge there are no autocatalytic zinc processes. Immersion (displacement) plating of zinc onto aluminum is possible though, and is in fact the first step in electroplating onto aluminum. Ahmad proposes an ionic plating method below, and Marvin proposes a 'contact method' using aluminum.

If we define 'electroless' more broadly, you can do mechanical plating of zinc or sherardizing of zinc onto certain types of stuff.

Luck & Regards,

A. Hi again. Please specify exactly what you are hoping to do. I've already said there is no electroless (autocatalytic) zinc plating process. Are you looking to do 'zincating' (immersion/displacement plating) on aluminum, magnesium, or beryllium? What kind of parts, what alloy or material, and why? Thanks.

Lowenheim's Modern Electroplating should be available in a library or fairly cheap in the used book market, and many other plating books cover zincating as well. Good luck.

Regards,

Hi again Ralph.
Hot-dip galvanizing works only on steel parts; mechanical galvanizing only on tumble-able parts; "cold galvanizing" is just zinc-rich paint; zinc-nickel plating offers some of the corrosion-resisting ability of cadmium, but certainly not the malleability nor the galvanic compatibility with aluminum that cadmium offers ... so it can be a substitute for cadmium in certain applications; but for other applications, other substitutes will be better.

It's time-consuming & difficult to answer even very clear, highly detailed questions, so when I ask you twice to please explain what you are trying to do, on what kind of parts, of what material, and why -- so that I can at least try to do so -- but instead of answering me you just post under a different name, adding more abstract questions which also can't be answered without a dozen ifs-ands-&-buts, sorry, but I think it's peace out for me for now :-(

Apologies & Regards,

A. If you take a look at Roberto's note from 2003 I would like to put it into historical context. Over 50 years ago, Chrysler (now Stellantis) had a hydrogen embrittlement issue with electroplated single wire hose clamps. This was fixed by going to mechanical plating and this was the first extensive use of mechanical plating. Mechanical plating does not fall into the normal description of electroless plating (i.e., a plating process incorporating a reducing agent) but it does not use electricity to deposit the zinc.