finishing.com -- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing

HomeFAQsBooksHelpWantedAdvertiseForum
topic 7964

Do Copper Braze Joints Present an Adhesion Problem for Alkaline Zinc?


(2001)

Do copper braze joints present an adhesion problem for an alkaline zinc line? The parts are processed as follows,

  1. Machined from low carbon steel tubing
  2. Brazed to an adapter (SAE 1015)
  3. Bent and packed for plater
  4. Plated Zinc with yellow chromate
  5. Powder Coated

After powder coat we are having blistering and poor adhesion only in the areas of braze flash or overrun. Our braze is 92% Cu and 8% Sn.

Any help, opinion, or feedback would be appreciated.

Kevin Davis
- Versailles, Kentucky, USA


(2001)

We plate parts that have copper braze with alkaline zinc all the time, so it can be done. Sloppy brazing will be a problem, however. We do not powdercoat after the zinc yellow, so I don't have specific knowledge about that. However, you should monitor your zinc bath and chromate bath for copper (and iron) contamination. You can do this with atomic adsorption (AA) equipment.

tim neveau
Tim Neveau
Rochester Hills, Michigan



This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Q or A to THIS thread START a NEW THREADView This Week's 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


©1995-2017 finishing.com     -    Privacy Policy
How Google uses data when you visit this site.