-- The Home Page of the Finishing Industry

on this site
current topics
The world's most popular metal finishing site, and the internet's friendliest corner

topic 17434

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


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


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

If you have a question in mind which seems off topic, please Search the Site

ADD a Q, A, or Comment on THIS topic START an UNRELATED topicView CURRENT HOT TOPICS

Disclaimer: It's not possible to 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 may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2019, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.