Questions about electroless plating

[J Tiers]

I have seen it for nickel, which is probably what I want. But are there any other plating types done that way?

This is for the steam plant toy that I am renovating for/with my friend. The repaired and replaced parts are brass, and the originals seem to be nickel plated brass.

There will have to be some soldering done to the fittings that are plated, does the electroless hold up to that? I can't do it after, because I figured the solder will "poison" the surface for plating, and in any case solder is very soft so if it did plate OK, it would probably not last. Certainly it would not last through any later work that might be done which involved loosening those solder joints, so it seems plating before any assembly work is best.

[Doc Nickel]

While I'm not aware of any other self-plating metals (maybe cadmium?) the electroless nickel kits (Caswell, et al) work just fine on brass.

Now, the trick is that the electroless will not 'catalyze'- or whatever the term is- on brass, without a bit of iron or steel. Once the process starts, the rest plates out just fine, but it has to have that catalyst.

Also, the brass has to be clean, clean, clean. Zero tarnish, zero oxidation, zero oil, no paints, etc. My usual trick was to scrub in warm water with a bit of detergent (or hand cleaner) then a thorough rinse in hot water, then into the nickel solution while it's still wet. Usually a chunk of clean baling wire as a hanger, or wrapped around an inconspicuous spot, will be enough to start the reaction.

You can't just toss the parts into the solution- screws and whatnot will "plate" themselves to the bottom of the vessel, and/or you'll get unplated shadows where the solution couldn't get to.

Do NOT use a metal vessel for the solution- aluminum, enamelled steel, stainless steel, etc. The solution will react with all of them. It might not "plate" them, but the nickel can start playing to itself and fall out of the solution as crystals. Glass is best, and don't use good cookware- you WILL get spots of plating that will not come off easily.

As I was doing small parts (paintball gun bits) I'd just buy cheap coffee pot carafes and use an old hotplate. Oh, and hotter is not better. Just short of boiling is fine. It plates as fast as it plates, and hotter just gives you a rough finish.

Doc.

[J Tiers]

That sounds like great advice. Thank you!

How thick is the plating ? Not how many microns, but is it thin enough to scratch through quickly, or can it get to be reasonably tough?

[psomero]

Good electroless nickel is very hard and fairly thin (.0005-.0015 in range)

If you do it right it bonds well to the substrate and it is very durable. I have experience with commercial plating, not the DIY stuff though...

[JRouche]

[QUOTE=J Tiers;n1991313]This is for the steam plant toy that I am renovating for/with my friend. The repaired and replaced parts are brass, and the originals seem to be nickel plated brass.

There will have to be some soldering done to the fittings that are plated, does the electroless hold up to that? I can't do it after, because I figured the solder will "poison" the surface for plating, and in any case solder is very soft so if it did plate OK,"""

I like this project, very nic,

No, I dont think to coat any lead anymore. Lead filler ,, The nick might not stick is all Im sayin. I do like the original look with the raw lead seal and all the refurbished stuff around it. Sorry, went off tangent. Darries fault :}
JR

[ed_h]

Copper will self-plate on steel, but the durability depends on the exact copper solution chemistry.

There are commercial tin solutions that will self-plate on copper and probably brass.

Ed

[Rich Carlstedt]

What Doc Nickel said is dead on with all his comments and the ideal temp is 192-194 degrees for technical purposes for Electroless Nickel (EN)
.0005" is considered "Flash" plating and will handle general wear.
I doubt you will get it to coat the solder and if you used any Chlorides (coolant, solder flux ) in making the parts, forget any long term
use as adhesion becomes null. ( Chlorine atoms are the enemy) if the nickel sticks at all.
When we plated our die parts with EN , clean razor blades (super clean) were measured and hung in the tank and removed (just one) after 5 or 10 min. and measured.
The mike will read double the coating thickness and you project the time is takes to get what is desired. ( Razor blades are cheap and very consistent thickness steel

Now there is another avenue, and it is used generally to repair EN parts and that is "Brush Plating" and is a much slower process.
You can use the same EN mixture and cleanliness but apply the coating with a voltage source. Your part is grounded and you use a Wand (Electrode)
made of nickel that has a cotton wrap and is wet with EN fluid and rub it on the surface . The voltage (~ 2-10 DC) drives the Nickel atoms into the metal part.
I have no experience with lead , so can't say how that would work but think it may be feasible. In Essence , you are doing Electrical Plating , instead of Electroless Plating.

Rich

[J Tiers]

Nothing soldered yet, and won't be until after plating.

There is a good deal of work to be done (not by me) before the device is re-assembled, since as you can see, the paint is mostly leaping off the surfaces, and is missing from many areas already. The issue of "collectible value of original paint" is fairly moot, and the thing isn't mine anyhow.

[BCRider]

In the distant past I worked for a local SSB radio outfit. My time was split between sheet metal and PCB fabrication. We had options for electroless tin, gold and nickel. The tin and gold were used for plating the copper traces. The nickel was the substrate for electro plating gold on the fingers for PCB connectors.

All of the electroless plating options were pretty well self limiting and were very thin as a result. Once the copper (or I imagine brass due to the copper contest) is covered there's nothing left to cause the exchange reaction. And of course tin and gold being soft to begin with the plating was also easily scratched. The nickel got a very light polish with a sponge and some light duty abrasive cleaner then well rinsed and brushed with a toothbrush to polish the nickel It brightened up nicely from this light polishing so it was clearly somewhat scratched by the process. Or it may have only removed some surface smut caused by the process.

[nickel-city-fab]

Would silvering work instead of nickel? Pretty sure you can solder directly over that with tin-lead, with no ill effects. Clockmakers have a product called "horosilv" for just this task, link here: https://www.hswalsh.com/product/dial...orosilv-hs1481

Just rub it in with a piece of damp cotton or flannel.
Of course you would have to lacquer the parts afterward to keep tarnish away.

[old mart]

I was a qualified electroplater (metal finishing technician) back in the mid to late 60's plating on plastic and through hole plating of circuit boards for mainframe computers. We mostly did copper and nickel. To get the solutions to plate on non metallic surfaces a catalyst made from palladium chloride and hydrochloric acid was used. We also did some tin and tin-lead. With the copper and nickel, if the thickness of the coating was to be increased,then the work was transfered to conventional plating baths. When I look at a cheap Chinese circuit board and admire the through hole plating, it shows just how far things have progressed in the last 55 years.
One thing I always remember was using a 5 gallon glass jar with 4 gallons of electroless nickel solution on a hot plate. We had wrapped the jar in insulating tape to make it slightly less dangerous, and used it for at least six months with many batches of plating solution. When the solution becomes close to the end of its life, it plates all the remaining nickel on the insides of the jar. That has to be removed with nitric acid. I had just finished cleaning and rinsing the jar when it slipped out of my gloved hands and crunched onto the floor minus its bottom.

[Astronowanabe]

continuing with Nickel fab city's silver suggestion https://angelgilding.com/ sells stuff that might serve.

[Rich Carlstedt]

You can Tin/Lead solder to Nickel after plating . That's what they use to do with Tin Cans . They soldered the seam and used acid flux in case it was contaminated and used 98 % lead solder as well. They called it 2-98and at a 605 F degree temp. Higher Tin composition helps !

Rich

[JoeLee]

I've used this stuff before. https://www.cool-amp.com/cool-amp

JL....................