The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Gold plating on stainless steel to pass nitric acid test

 

I have a stainless steel tube (#304) with a OD of .021 and an ID of .015. I would like to gold plate the inside and outside of this tube with a 10 to 20 mil gold layer without a base nickel layer. The nickel used in the past will not hold up to an 40 second submersion in nitric acid that I need to pass. Any suggestions?

Lenny Davis
- Kansas City, Kansas

---

Have you tried using an acid gold strike?

Neil Bell
Red Sky Plating

Albuquerque, New Mexico

---

Is your gold suffering from porosity? Try a mild steel panel and test with a ferricyanide / sodium chloride solution for porosity. This could by why the nitric is eating the nickel.

Martin Trigg-Hogarth
surface treatment shop - Stroud, Glos, England

Have you tried using an electroless nickel process with a high phosphorous content. These processes can withstand nitric acid better than nickel on its own.

Sharon Banner
- England

As recommended before a Hi-Phosphorous coating is a good resolution, The amount of gold you require is significant, if I am reading correctly, shouldn't the gold be enough? Anyway there are more than one solution, duplex coatings, etc

Richard Webb
- Toccoa, Georgia

We are trying to accomplish a similar requirement, plating the exterior of a .043 OD 304 stainless steel tube. It will be used as a short term implanted medical device. Have you found a solution? Nickel is not desirable due to it's poor compatibility with the body.

Thomas Youd
- SLC, Utah