Topic: Stripping of Phosphate Coatings

Dear Forum, Greetings from India.

Am a newbie to this forum and hope that am welcomed. Thanks in advance.

We have a phosphating section here for Cold Forming of components as well as for coating before painting. At times when the phosphating quality is not achieved as per our requirements, we need to strip of the Phosphate coating on the components.

Could anyone help me in advising me which is the chemical to be used and whats the concentration? Or is there any chemical readily available in the market for stripping of the same.

Thanks and regards.


Re: Stripping of Phosphate Coatings

Dear Newbie,

I hope you have not been STUCK waiting on this post!!?? You can begin by using an industrial grade acid, such as Hydrochloric Acid z(HCl Acid), aka Muriatic Acid. It usually comes in raw form of about 37% wt. by volume, this I would refer to as concentrated. Depending on the phosphate coating thickness, and desired time in which you would like to strip the coating, and in addition, the type of base material you are stripping the phosphate coating from, you should be able to accomplish this with a 20% - 50% vol. concentration of HCl acid. The time will be dependent on the coating thickness, but I would guestimate approx. 2 - 5 minutes. Let us know how this works out.



Skelton, hOST


Re: Stripping of Phosphate Coatings

I agree with Skelton, but be aware that continued exposure to hydrogen (via the acid) can and will cause hydrogen embrittlement (as may the phosphate, too).

-Dustin Gebhardt, CEF

Advanced Manufacturing/Finishing Engineer


Sanford, NC