Home /
T.O.C.
FAQs
 
Good
Books
Ref.
Libr.
Advertise
Here
Help
Wanted
Current
Q&A's
Search 🔍
the Site
pub Where the world gathers for
plating, anodizing, & finishing Q&As since 1989





-----

Sulfuric Acid coagulation issue





2003

Our continuous anodizing line comprised of usually 20-25% tech. grade Sulfuric Acid has had recent issues of coagulation when either the concentration spikes (25-30% sulfuric) or if ambient temp. drops below 70 degrees. The solution turns a iridescent pearl color and looks of oil. Can anyone explain the reason? Solids form at the bottom of the tank and only water or elevated temp. will break it.?

Jason Von Marschner
- Ontario, California, USA



2003

I'm having a bit of a hard time picturing it, but it sound like you have too much aluminum in the bath and it is precipitating. Decant those solids out of the solution.

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey



2003

Running at 25-30% acid is in my opinion very high. It may be that way because you have a very high Aluminum content. Check the aluminum content out and if it is over 12 oz per gal decant. Also check for copper.

drew nosti
Drew Nosti, CEF
Anodize USA
supporting advertiser
Ladson, South Carolina
anodizeusa1


none
finishing.com is made possible by ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages



(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

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:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact    -    Privacy Policy    -    ©1995-2023 finishing.com, Pine Beach, New Jersey, USA