-- The Home Page of the Finishing Industry
Serious Education & the most FUN
you can have in metal finishing smiley

No popups, spam, registration or passwords
on this site
current topics
topic 9661

Barrel burnishing aluminum/zinc


We are having trouble obtaining a satisfactory burnished finish on Aluminium (various grades) and zinc based materials (myzac etc) with a rotary barrel polisher.

We have moved from mainly carbon/stainless steel polishing and so have been using carbon steel mixed shot with various compounds, all of which are resulting in some form of staining (either grey or yellow) on the parts. I have been advised to try stainless shot and/or a different compound

We are a little unclear as to whether we really need to change to stainless shot (obviously more expensive) or whether we can just use a different compound, we are looking for a burnished mirror finish.

Any advice would be appreciated.

Thanks in advance,

Will Hamlyn
Logic plc - London, UK


Will, the yellow/gold staining you see on the aluminum and zinc is probably due to immersion plating of iron for your steel shot. When you were finishing other ferrous parts, immersion plating was not a problem. Now that you are finishing aluminum and zinc, both more chemical active than iron, any soluble iron plates out on the more active aluminum or zinc. The plated iron gives the part the gold color.

To prevent this, you need to switch to a more chemically inert shot. It will be very difficult to solve this problem with another compound. In addition to stainless steel, you may want to consider ceramic shot.

Roy Nuss
Trevose, Pennsylvania, USA


Suspected that may be the case, thanks for your advice, time for some new supplies.


Will Hamlyn
Logic plc - London, UK

June 29, 2009

Have you looked into low plasticity burnishing? it provides the mirror finish and compressive stresses without the need for shot peening. may solve your problem without needing to buy different supplies or change materials.

Julie Prevey
- Cincinnati, Ohio, United States

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

ADD a Comment to THIS thread START a NEW threadView CURRENT 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

©1995-2018, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.