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


Hard Anodize - temperature - Pore density question

May 21, 2010

Can anyone give me an idea as to the different pore densities that would be produced by a hard anodize process - where the only difference was temperature? The bath concentration levels are the same for each of the three temperatures. the amps/ft2 are all run the same (say 35 amps/ft2). What would be the pore density difference between a bath that was 45 degrees, a bath that was 35 degrees and a bath that was 30 degrees? My understanding is that temperature obviously keeps the part cool from all the current running thru it - but does it not also have an influence on the shape and size of the pore?

Wedge McFrody
product designer / ex anodize job shopper - Houston, Texas, USA

May 26, 2010

Quantitative data has not been published because the answer is in multiple variables. The general rules are: the warmer the solution then the larger the pores (less Taber Abrasion), the higher the free acid then the larger the pores, the LOWER the current density then the larger the pores. Glycolic/glycerin additives make the pore smaller.
old fashion oxalic acid makes the pore smaller. That is four dimensions right there and we have not added in dissolved aluminum, alloy, etc.so no hard numbers.

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