Home /
Search 🔍
the Site

Chime right in! (no registration req'd)


"Tri cationic phosphating"


I am a metal engineer. I study about converting coating (tri cationic phosphating bath).my coating bath buy from henkel company.

My process stages consist of:oil cleaning-acid washing (sulfuric acid 5%)-water rinse-phosphating bath-water rinse

The result coating is very smooth,dense and light gray color.but after two time immersion coating the bath is not work good.my coating pieces are steel plates.(st37)
how can I improve the bath?
must I add other materials in working bath?
what are the best conditions of my bath?
what must I add to the bath for increase the saltspray time?
my bath sludge is very high.the way of coating is immersion. how can I solve this problem.
the water that I use is very hard. who can I solve this problem?

Hamed Khakzad
amirkabir - Tehran


You should go back to Henkel and get some more advice, it is not normal at all to have a acid degreasing tank prior to Zinc Phosphating,this should be an alkali cleaning degreasing bath.Prior to Tricat phosphate it is normal to have Alkali wash 2x,rinse,conditioning rinse or conditioner spray then tricat phosphate.

A Wagstaff
- Lincs, UK


what do I do to improve the zinc pot bath ?
thank you.

Saeed Biabani
- Iran


No one can possibly help you improve your bath until you say what it is, Mr. Biabani.

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

August 19, 2010

Dear Mr.Hamed,

Please ensure the ratio of total acid to free acid per 10 lots, also ensure accelerator concentration in the bath.
You need to maintain TA:FA ratio along with the concentration of an accelerator. This will help you for consistent results.
You can also Off-line your derusting (Acid) bath for better maintenance of your phosphate bath.

Rahul Deshpande
- Aurangabad, Maharashtra, India

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

Q, A, or Comment on THIS thread SEARCH for Threads about ... My Topic Not Found: Start 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    -    ©1995-2021 finishing.com, Pine Beach, New Jersey, USA