How to Remove Teflon Impregnation from Hardcoat Anodize

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Thank you for visiting www.finishing.com, Paul! Could you please flesh out your actual situation rather than leaving it as an abstract question? Thanks!

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004

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A. Okay then, from Wikipedia: "certain alkali metals and most highly reactive fluorinating agents".

I'm really not trying to make it difficult for you to get help! I'm just asking what our readers have to know in order to be helpful, Paul. Teflon is extremely chemically inert; you certainly won't find any acid, alkali, or other common chemical that can dissolve it.

- So is it okay if the suggested chemicals destroy the hard coat? -- dissolving the hard coat with chromic-phosphoric acid sounds like the best approach to me.
- Must the removal be selective, or can you strip all of the Teflon and all of the anodizing and start over?
- Are you talking about pharmaceutical or medical equipment, in which case even miniscule poisonous residues could be a major issue?
- Are you a shop which mistakenly applied Teflon to a single part you are trying to salvage, or do you need a production process which applies the Teflon before some manufacturing operation, and then must strip it by dipping in open-top tanks? A highly reactive fluorinating agent might prove okay for stripping Teflon from one rework part under a lab hood, but it is out of the question to fill open-top production tanks with such chemicals.

Good luck!

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004

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2004

A. Paul,

1. How thick is the anodic coating?
2. Are you sure its Teflon impregnated, and not bonded?
3. If your answer is yes to #2, how do you know? (I, like many others on this site, are not believers in TIA, as the Teflon molecules are too big to penetrate the anodic pores)
4. If its bonded, what type of Teflon is on top?, And how thick is it?
5. Do your parts have tight tolerances? Complex shapes?
6. Why not contact your vendor who applied the "TIA" coating (if it does, indeed, need to be removed) as the vendor would be the most knowledgeable on how to remove their coating.

You need to understand that things in the coating world are not quite as simple as you may think, there are numerous ways of removing the aforementioned coating, as long as one is familiar with how it was applied. Now ... what was your straightforward question?

Marc Green
anodizer - Boise, Idaho
(anodizer extraordinaire)

A. Paul,

It makes a difference what the part is. It would not be a great idea to strip a frying pan with a super strong solvent as some will soak into the anodize. Teflon impregnated anodize is mostly a myth as the particle size of the Teflon is normally larger than the pore size of the anodize and is especially true on hard anodize. Thus, it is a very adherent, heat set "paint". Teflon is like saying automobile-There are many! Each one has slightly different chemical makeup and properties. So, what is your part used for and how many do you have to strip? My 2 cents worth, it probably is not cost effective.

James Watts
- Navarre, Florida
2004

A. Paul, there are hundreds of Teflon@ coatings available. Who knows what type you are using? The manufacturer of the coating will know best how to apply and remove their product from your materials. Call the product supplier.

Bill Grayson
metal finishing - Santa Cruz, California
2004

A. Hello,

I actually have to remove teflon impregnation from an anodize surface today. Teflon is per the AMS2482. I do agree the vendor should know how to remove the tefloned anodize. I'm going to remove the teflon along with the anodize in an etch bath. The same way you would remove anodize without teflon. The etch bath should break the seal. The teflon that I sealed the parts with is a thin layer that impregnates the pores of the hard anodize. I hope this helped....

Amanda Yeager
- Phoenix, Arizona
June 18, 2008