Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
-----
Should EN baths have wetting agents or not?
Q. I am starting into electroless nickel plating. I have tried 3 different baths from 3 suppliers, and all baths apparently came without wetting agent. Is there any reason to use no wetting agent in EN baths? There was something like pitting on the parts plated with low-phosphorous nickel, so I thought that proper wetting agents would help. I will appreciate any experience or opinion.
Thanks,
FRANTISEK HAASglass products - JABLONEC N.N., BOHEMIA, Czech Republic
2003
A. This seems to be a complaint to your suppliers. What do they have to say about it? Every chemistry is different, so it is very difficult to recommend an addition not knowing what is in your bath,
G. Marrufo-Mexico
Guillermo MarrufoMonterrey, NL, Mexico
2003
A. Good question. Generally alkali electroless nickel baths don't have wetting agents, but many acid based baths do include them. Wetting agents are there to make the substrate more wettable and with alkaline baths, especially ones using sodium hydroxide, have a "built-in" wetting agent, namely caustic soda ⇦liquid caustic soda in bulk on Amazon [affil link] . Conversely, acid based baths don't have this luxury.
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2003
Q. Guillermo,
I don't complain to my suppliers, I only wonder, why there is no wetting agent in EN baths. Other weak acid processes (electroplated nickel or zinc) always use wetting agents, so why not EN? Is there any fundamental reason? Trevor says, there is not. Many thanks for your responses.
FRANTISEK HAAS [returning]glass products - JABLONEC N.N., BOHEMIA, Czech Republic
2003
A. Wetting agents are usually not necessary in electroless nickel plating solution because the hydrogen gassing occurs quickly enough that bubbles leave the surface without causing pitting. Why add something (wetting agents, i.e., surfactants when not needed?) Some surfactants are or become organic contamination to electroless nickel plating solutions. If there is oil or other organic contamination introduced into the EN plating solution, wetting agents will help temporarily, otherwise they should be avoided. There are only a few wetting agents suitable for electroless nickel solutions. If pitting is encountered it is almost always because of improper preparation, i.e., something is left on the part, not removed by cleaning, or there is a pit in the basis metal that has entrapped cleaner or other materials.
Don Baudrand
Consultant - Poulsbo, Washington
(Don is co-author of "Plating on Plastics" [on Amazon or AbeBooks affil links]
and "Plating ABS Plastics" [on Amazon or eBay or AbeBooks affil links])
2003
Choosing surfactant for electroless nickel plating
Q. Hi,
Im currently doing research on electroless nickel plating (with pH 4 and operating temperature at 80 °C), and I want to purchase surfactant to add in it, but there are so many kinds, nonionic, anionic, cationic, and amphoteric. I've seen some people using nonionic (Triton X-100) and anionic (SDS) most frequently. which type of surfactant is the most suitable for metal plating bath that the surfactant won't participate or interfere with chemical reaction of plating bath?
Thanks
- san jose California, USA
December 17, 2014
A. Hello Kevin,
I have to fully agree with Don Baudrand's answered letter above your question. I think Don covered all the bases.
Process Engineer - Phoenix, Arizona USA
December 20, 2014
this text gets replaced with bannerText
Q, A, or Comment on THIS thread -or- Start a NEW Thread