
plating, anodizing, & finishing Q&As since 1989
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What is 'P ratio' in zinc phosphating bath and how to determine it?
1998
Q. Can someone tell me a method of determining the "P ratio" of a zinc phosphate conversion coating? If you know of a testing laboratory that can provide this analysis I would very much like to know of that.
Dave G [last name deleted for privacy by Editor]Ohio
Ed. note: Sorry, this RFQ is outdated so private contact is no longer available, but public technical replies are still welcome! No public brand/source suggestions please ( huh? why?)
1998
A. ACT test lab in detroit - Assoma has an x-ray machine for coating weight.
Jeff B [last name deleted for privacy by Editor]- Windsor , Ontario , Canada
2005
Q. Can anyone throw light on P ratio in zinc phosphating bath.
Manish [last name deleted for privacy by Editor]UL - India
2005
A. The P ratio is a measure of the forms of phosphate obtained from zinc phosphating. Miyawaki, Okita, Umehara and Okabe(1) proposed that P ratio = Phosphophyllite (Zn2Fe(PO4)2.4H2O)/[Phosphophyllite + Hopeite (Zn3(PO4)2.4H2O)].
They found that the P ratio was higher in dip applications with a low Zn:PO4.
The P ratio may be affected by a number of factors, including temperature, agitation and method of application.
(1) Miyawaki, T., Okita, H., Umehara, S., and Okabe, M., Proc. Interfinish 80, Kyoto, 1980
Brian TerryAerospace - Yeovil, Somerset, UK
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2005 Q. 1) What exactly the definition of 'p'ratio in zinc phosphating process? Generator manufacturer - Rudrapur, Uttranchal, India 2005 A. Dear Neeraj, ![]() T.S.N. Sankara Narayanan - Chennai, Tamilnadu, India (ed.note Nov. 2017: The good doctor has a fascinating blog at https://advancementinscience.wordpress.com) |
December 9, 2011
Q. Can you give me the details for how to calculate p-Ratio of phosphate bath?
We have completed SEM (Scanning Electron Microscope)for phosphate panel.
Sr. Engineer,AME - Satara, India
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Ed. note: We appended your inquiry to a thread which hopefully answers it. Please advise of remaining questions.
Q. I want to understand ... what are the Factors effecting P-Ratio?
Can anyone help me by giving reference of some good online study material?
Have to make an Official report (Fish-Bone diagram).
I am virtually Illiterate in this Subject.
- Jamshedpur, Jharkhand, INDIA
May 14, 2012
July 6, 2012
Q. I want to ask the method to determine Phosphate ion and zinc ion in Tri-cationic phosphating bath in order to monitor the coating pattern on mild steel.
Thanks and regards
- lahore, Pakistan
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