No passwords, No popups, No AI, No cost:
we earn from your affiliate purchases

Home /
T.O.C.
Fun
FAQs
Good
Books
Ref.
Libr.
Adver-
tise
Help
Wanted
Current
Q&A's
Site 🔍
Search
ted_yosem
Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
finishing.com -- The Home Page of the Finishing Industry


  pub
  The authoritative public forum
  for Metal Finishing since 1989

-----

Scalloping In Heavy Electroless Nickel Deposits




We have observed a condition in heavier (>.001") Electroless Nickel deposits which we call "scalloping". It happens only adjacent to masked areas, whether taped or plugged. Plug or tape material doesn't seem to matter. Nylon, neoprene, silicone, EPDM, Teflon, rubber all do it. So far, the only way to avoid this has been adjusting the part design, (i.e. adding a generous chamfer or counterdrill around holds to be plugged. This gets the "scalloping" away from functional surfaces.

The condition appears to be a partial hydrogen pit, sometimes hemispherical, sometimes less than hemi. If parts cannot be redesigned, what would be suggested for a bath modification? We already have an anti-pitter in the Electroless Nickel bath, and never get pits on surfaces that are not adjacent to masking, even in very heavy deposits (>.0025").

Jim Morse
- Marlboro, Massachusetts
2002


You didn't mention what is your substrate and prep cycle but is sounds like you need to improve your pretreatments. Plastics, rubbers and other materials used as maskants are hydrophobic. The techniques used to prepare plastics to be plated were developed to deal with this condition and make them hydrophilic, and might help you.

Guillermo Marrufo
Monterrey, NL, Mexico
2002


I experience the same thing at times, but it appears also on sharp edges. I suspect stabilizer adsorption here. I'm working on this.

Kevin Keating
finishing - Rochester, New York
2003




(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Finishing
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g,
& Software


About/Contact  -  Privacy Policy  -  ©1995-2024 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"