Aloha, fun & authoritative answers -- no cost, no registration, no passwords, no popups
(as an eBay Partner & Amazon Affiliate we earn from qualifying purchases)

Home /
Site 🔍
pub  Where the
world gathers for metal finishing
Q&As since 1989


Ni/Zn Passivate adhesion post Ni/Zn plate

Q. We paint parts that have been treated with Zi/Ni AMS2417 type 2, but sometimes we have adhesion problems on some of the parts in the batch.
Wet paint system is according to MIL-PRF-23377 [on DLA] type 1 and MIL-PRF-85285 [link is to free spec spec at Defense Logistics Agency,] , when we test the paint at aluminum test panels treated with MIL-DTL-5541 we do see any problems.
Is there something in the Zi/Ni process that can improve the adhesion of the paint, and the other way around is there something in the process that have a negative impact to the adhesion.
We degrease the pars before we paint them, and do the "water on goose test".

Poul Slot Mikkelsen
- Denmark Vildbjerg
January 19, 2022

⇩ Closely related postings, oldest first ⇩

Q. We have been using a Zinc-Nickel plate tank for sometime now using the E-Bright solutions provided by EPI / Electrochemical Products Inc. [a supporting advertiser]. We are also using the post chromate treatment (Ni/Zn Passivate). Well we had been using that post chromate at an ambient temperature and then Boeing came in and said that it had to be at 100 °F ± 5 °F per BAC 5637. Since raising the temp to 100 °F, we have had nothing but adhesion problems which were not there prior to raising the temp. The manufacturer recommends 70-85 °F. Has anybody else out there had any situations like this? Can you offer any advice or suggestions?

I would appreciate any help.

Tony Schmaltz
- Kent, Washington

A. Tony,

Bath temperatures above 90 °F cause a loose deposit according to the following reference. Jack Kinder, "Chromate Conversion Coatings" American Electroplates' Society, Inc., 1986.

Best Wishes,

Mary Cera
- OKC, Oklahoma

this text gets replaced with bannerText
spacer gets replaced with bannerImages

(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:

Chemicals &
Consult'g, Train'g
& Software

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