-----
Phosphating of Cast Iron?
Quickstart:
Cast iron components may be phosphatized as a pretreatment before painting, or as a final coating if the parts will be bathed in oil rather than exposed to the atmosphere.
Phosphatizing is not a good final finish for general atmospheric exposure.
Want literature on phosphating cast iron
Q. DEAR SIR,
KINDLY SEND ME SOME INFORMATION OR LITERATURE ABOUT COMPLETE METHODS OF METAL FINISHING {PHOSPHATING} OF CAST IRON. I SHALL REMAIN THANKFUL TO YOU. LOOKING FORWARD TO HEARING FROM YOU SOON.
YOURS SINCERELY
muhammad akbar- lahore-Pakistan
2000
A. Dear Mr. Akbar:
We're pleased to print your inquiry, and if you have a highly specific question I think a reader will answer it ... but when your want to read about "complete methods", I suggest that you consider the classic texts on phosphating ⇨
You might also check our Directory of Chemicals, and write directly to some suppliers. Good luck!
Regards.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Iron phosphating on Cast Iron
Q. I am interested in knowing whether TT-C-490 [from DLA] , Method Type II (iron phosphate) can be applied over cast ductile iron without any problems. I know that it can be applied over forged steel, but was wondering about the cast iron. The chemistry of the cast iron conforms to ASTM A536, Grade 60-40-18. Also, are there any manufacturers that have baths suitable for treating a pipe that is approximately 5-ft long? Thanks, Marc
Marc PepiUS Army Research Lab - Aberdeen Proving Ground, Maryland, USA
2001
A. Iron Phosphate coatings will form on cast-iron with no problem, getting a good coating without flash rust is a little more of a trick. Many shops can process a five foot piece of pipe, some can even do it in large quantities on a conveyorized line. Assuming your part is to be coated after phosphating, you will most likely need a good rust inhibiting final rinse, and a fast dry cycle to get the water off before it can pull out too much iron.
Jeff Watson
- Pearland, Texas
Manganese Phosphating on Cast Iron
Q. Sir,
We are not professional platers but have a machine shop. We are trying to phosphate some of our Cast Iron components, viz. Manganese Phosphating to get a jet black coating on the same. We tried blackening of the same components but the vendors here in India could not overcome the redish tinge colour on the blackened surface of our castings.
While doing the process of Manganese Phosphating we are facing two problems.
1) The black colour deposited on the component does not adhere perfectly to the part. If we rub it with our hand , they become black as the colour is rubbed on our hands.
2) The black colour of phosphating is slightly like dark grey type and not jet black.
Can you suggest any solution.
As we are not professional platers we are doing all this process in a S.S. bucket , consulting our local chemical supplier of phosphating compound.
After phosphating , is it necessary to apply oil on the phosphated surface and does it have any relation with adhesion of the deposit on the part.
With Regards,
- Kolhapur, INDIA
March 24, 2009
? Dear Ashwin,
Do you need Manganese phosphate coat only for the look? The colour will range from grey to black, but you cannot control it. If you are doing it for aesthetics, please try zinc black.
- Aurangabad, MS, India
[editor appended this entry to this thread which already addresses it in lieu of spawning a duplicative thread]
Q. I am having trouble with phosphating of cast iron; please suggest the compositions of chemicals and the process for optimal results.
- Delhi, India
March 2, 2012
A. Hi Kiran. Are you attempting to iron phosphate, zinc phosphate, or manganese phosphate these components? Please briefly describe what you are currently doing and trying to do.
Thanks and regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Q. Facing issue of rust formation in Grey Cast Iron parts with internal cavities after Mn Phosphate and Waxing. Rust formation takes place after one week with white and then converts to red rust as no. of days increase.
Suggest to resolve the issue.
- new delhi, India
March 28, 2019
A. Hello,
Check on process parameters carefully, you are overlooking something somewhere.
Khozem Vahaanwala
Saify Ind
Bengaluru, India
A. Improve your rinsing.
Apply a rust preventive. Oil is okay.
Jeffrey Holmes, CEF
Spartanburg, South Carolina
A. Hi Kapil
Khozem is right up to a point, but Jeffrey may be explaining the actual problem: manganese phosphate is usually a "break-in" coating for engine parts, etc., which will be bathed in oil rather than exposed to atmospheric conditions.
Tell us about your oiling procedure or rust-proofing procedure because expecting parts which are not oiled or rust-proofed to not rust isn't going to work out. I have seen phosphatized parts be stripped of their oil and then flash rusting within 20 minutes.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Q, A, or Comment on THIS thread -or- Start a NEW Thread