Home /
Search 🔍
the Site
pub Where the world gathers for
plating, anodizing, & finishing Q&As since 1989


Type 2 Black Anodizing Discoloring

August 25, 2010

My company makes motorcycle exhaust tips and we are having trouble with them staying shiny black over time.
The tips are 6061 aluminum, machined, polished, bright dip black anodized type 2, laser engraved with our logo, and then teflon coated.

The teflon coating eliminates problems we were having with UV discoloration. When left in the sun, the exposed sign would turn brownish whereas the rest of the part would remain black. When running on a bike, however, they are exposed to a constant heat and over time (2 weeks to a month) they are turning a shiny purple color.

The look is extremely important. Going to type 3 anodize I was not able to get the same shiny clean black look that we want. Ceramics and other finishes, same problem. Is there a way to get a type 2 black anodize that won't discolor from the heat? I've read about teflon impregnating or sealing. Is this something done instead of a standard nickel seal?

Jenny Truant
Procurement for company - Santa Ana, California, USA

August 27, 2010

Organic Black Dye will fade with temperature. The anodic coating will crack with temperature.There is no fix to correct the problem of cracking and fading.

robert probert
Robert H Probert
Robert H Probert Technical Services
supporting advertiser
Garner, North Carolina

finishing.com is made possible by ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages

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    -    ©1995-2023 finishing.com, Pine Beach, New Jersey, USA