Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Removing Teflon from cookware
argyrium
Hazard to Others
***




Posts: 123
Registered: 3-2-2008
Location: Pacific
Member Is Offline

Mood: No Mood

[*] posted on 4-4-2012 at 11:20
Removing Teflon from cookware


Any suggestions on how one could "easily" remove the Teflon coating found on cookware - without destroying the aluminum.

It could be abraded off but that would be destructive to the metal.

I imagine heat at some point might cause delamination/charing but probably not below the m.p. of the metal and the toxicity is not something I'd want to be around anyway.

Any chemical combinations come to mind? I can't think of any, but something must be out there.

Thanks.

My reason for asking is that we have a lot of expensive heavy cookware and would love to get the PTFE coating off and still be able to use them.


[Edited on 4-4-2012 by argyrium]
View user's profile View All Posts By User
bfesser
Resident Wikipedian
*****




Posts: 2114
Registered: 29-1-2008
Member Is Offline

Mood: No Mood

[*] posted on 4-4-2012 at 11:35


Why on Earth would you even bother trying to do this?



View user's profile View All Posts By User
Bot0nist
International Hazard
*****




Posts: 1559
Registered: 15-2-2011
Location: Right behind you.
Member Is Offline

Mood: Streching my cotyledons.

[*] posted on 4-4-2012 at 11:38


Do to the chemical invulnerabilities (as designed) of the target, mechanical means are your best bet. Nothing, IIRC, could attack the PTFE but leave the Al intact.



U.T.F.S.E. and learn the joys of autodidacticism!


Don't judge each day only by the harvest you reap, but also by the seeds you sow.
View user's profile View All Posts By User
bbartlog
International Hazard
*****




Posts: 1139
Registered: 27-8-2009
Location: Unmoored in time
Member Is Offline

Mood: No Mood

[*] posted on 4-4-2012 at 13:29


Heat would work. Propane torch... you aren't going to melt a decent thickness aluminum pan with one, it's too good a conductor/radiator; and even if your pan is thin you would just have to move the flame around. But the toxic fumes would be very bad, you are wise to avoid this method.
Mechanical means - lead shot blasting maybe?
But overall: not worth the trouble. Just buy some cookware that doesn't have PTFE coating.




The less you bet, the more you lose when you win.
View user's profile View All Posts By User
Endimion17
International Hazard
*****




Posts: 1468
Registered: 17-7-2011
Location: shores of a solar sea
Member Is Offline

Mood: speeding through time at the rate of 1 second per second

[*] posted on 4-4-2012 at 13:30


I agree with bfesser. Why would one want to remove teflon covering and use naked aluminium pans? To have fried eggs, bacon and pancakes stuck to it? :D

Argyrium, if you're one of those "omg, chemicals in foodz!" people, you should google about aluminium. There's a scare about it, too. :D

Teflon is perfectly fine if you don't overheat it.




View user's profile Visit user's homepage View All Posts By User
chemrox
International Hazard
*****




Posts: 2953
Registered: 18-1-2007
Location: UTM
Member Is Offline

Mood: LaGrangian

[*] posted on 5-4-2012 at 09:45


You can buy oxide coated Al cookware. Or better use seasoned cast iron. IMHO the Teflon coated stuff tends to be cheap Chi-crap.



"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
View user's profile View All Posts By User
argyrium
Hazard to Others
***




Posts: 123
Registered: 3-2-2008
Location: Pacific
Member Is Offline

Mood: No Mood

[*] posted on 5-4-2012 at 12:06


Thank you all for the comments. I am less concerned about the Al in contact w/ food than the PTFE at frying/searing temps. Had a friend how lost a couple parrots from outgassing from this type of cookware. Guess they will just get pitched.

It is hard to beat a good cast iron skillet that has been properly seasoned.

BTW, Al pans can also be seasoned pretty well but do stick more than cast iron.

Thanks again.
View user's profile View All Posts By User
Gearhead_Shem_Tov
Hazard to Others
***




Posts: 166
Registered: 22-8-2008
Location: Adelaide, South Australia
Member Is Offline

Mood: No Mood

[*] posted on 5-4-2012 at 18:28


Anybody with birds knows not to have teflon-coated cookware in the house; they are exquisitely sensitive to the outgassing should the pans ever be overheated.

It seems to me, though, that you should be able to use stainless steel wool to strip the teflon. Back in the early '80s my ex-wife's grandmother borrowed my ex-mother-in-law's teflon-coated skillet. When she returned the skillet, it was bright and shiny. She commented on how hard she'd had to scrub to remove "that caked on crud." This was her introduction to Silverstone...

-Bobby
View user's profile View All Posts By User
Fossil
Hazard to Others
***




Posts: 131
Registered: 4-4-2012
Location: Canada
Member Is Offline

Mood: No Mood

[*] posted on 7-4-2012 at 15:05


you could try some aqua regia (sulfuric acid and nitric acid solution) to strip the teflon. I am not sure about teflon's resistance to aqua regia/ acids in general but I am led to believe that aluminium does resist AR quite well at room temperature.

I am in no way certain of this information but you could give it a shot, but since you are worried about teflon poisoning you probably don't want strong acids coming in contact with your cookware, along with everyone else.
View user's profile View All Posts By User
weiming1998
International Hazard
*****




Posts: 616
Registered: 13-1-2012
Location: Western Australia
Member Is Offline

Mood: Amphoteric

[*] posted on 7-4-2012 at 16:51


That won't work, as according to this, http://umanitoba.ca/admin/human_resources/ehso/media/Concent...
Teflon is resistant to even boiling aqua regia.

Also here, http://www.dynalabcorp.com/technical_info_ptfe.asp it says that only molten alkali metals and some boiling fluoridated compounds can attack Teflon. The only way to even make a progress on getting rid of that is boiling HF, but that is very implausible.

Probably just buy a new pan (as people suggested before) without the coating.
View user's profile View All Posts By User
peach
Bon Vivant
*****




Posts: 1428
Registered: 14-11-2008
Member Is Offline

Mood: No Mood

[*] posted on 8-4-2012 at 04:37


Take it down to the local car respray / paint joint and tell them you'd like it shot blasting. You can't chemically dissolve the teflon without also damaging the pan. It is resistant to aqua regia, hydrofluoric, sulphuric and the majority of other things.*

Keep in mind that the guys who shot blast things will likely have no idea what you're on about or why you want it doing, and may not be able to see much change in the surface as they're working. You could always test it afterwards with the addition of some hydroxide (if they're aluminium pans, you'll see bubbles forming as the hydroxide eats away at the aluminium). Be sure to tell them you only need the inside doing and it's specifically the teflon you want off. If they have the typical black appearance, you could ask them to blast back to the base metal as a visual cue.

After shot blasting, you'll have a nice rough surface for eggs to stick to, so it'll then need polishing back to a mirror. The typical black colour of teflon coated products is because the surface below has been micro etched to give the teflon something to grip onto. Even if you dissolved the teflon and poured it off (somehow), you'd still have to sort that subsurface out.

The possibility of teflon allowing harmful decomposition products to enter food products has been around since it first began touching pans, and it is now in just about every shop and every production line. However, things like oil or grease derived from the petrochemical industry are not allowed to enter food products (e.g. as mist or vapours coming from warm or fast moving parts) - so they do care about it. The discoverer of Teflon had no idea what to use it for and it was his wife who suggested putting it on the pans.

If you don't want to pay for shotblasting, you could always scrub it off with rough sand paper, then work up through the grades to something higher; see photos.

I really don't think it's a major problem at all. I'd much rather have teflon coated pans than bare. There are also harmful things within foods that are commonly accepted as okay.

Cassava root - the potato of some diets - cyanoglycosides
Stoned fruits (peaches / nectarines) - stone contains the same
Morel mushrooms - hydrazine
Mushrooms in general - good at picking up heavy metals
Cloves - high in eugenol, causes liver damage (I expect a lot of the other spice components do as well)

Some people won't eat Solanaceae members (e.g. tomatoes / potatoes) because Atropa Belladonna (deadly nightshade) belongs to the same family of plants. Potatoes will make you sick if you eat them while the skin is green, for instance.

*The only thing that might work would be boiling concentrated hydroxide in the pan, or melting hydroxide in there. Quite dangerous.

-----------------------------------------------------------------

To demonstrate what can be done with careful sanding, here are some chisels I bought. The one of the right is the factory finish.



Some time later, after patiently sanding the flat up through the grades against a piece of glass. I think I finished it with 2000 grit, having started with really coarse carbide floor sanding paper (might have even been 28 right at the start). I also bought a pack of diamond lapping compound from China (which comes as a multitude of colourful syringes going way up in grit number) and went on further to get a finish I could see myself in. Lapping compound goes a long way. With a pan, you could use a little buffing wheel in a Dremel or something like that.



:o



A corner the floor sander won't do.



Chop...



[Edited on 8-4-2012 by peach]
View user's profile View All Posts By User
Gearhead_Shem_Tov
Hazard to Others
***




Posts: 166
Registered: 22-8-2008
Location: Adelaide, South Australia
Member Is Offline

Mood: No Mood

[*] posted on 8-4-2012 at 06:06


Careful with the sharp tools, Peach. Blood rusts them up something awful ...
View user's profile View All Posts By User
INORGANICUM
Harmless
*




Posts: 11
Registered: 12-3-2012
Location: United Kingdom
Member Is Offline

Mood: GOOD

[*] posted on 8-4-2012 at 06:11


I guess you want the teflon to coat other things or you would just buy a new ally fry pan or cookware, in which case you would be better off looking for some "XLANE 1001 PAINT"(SP?) or get some of the new teflon bakeing sheets/cup cake moulds.
You could maybe use some solvent to disole it into or melt it. I have never looked into teflon but often thaught about it for coating things to use as chemical resistant alternatives to expensive glassware.
But given the price of cookware these days, it seems simpler to go shopping for a new pan+box of salt and season it yourself.
I think that couvers both sides of the coin. IN ORE
View user's profile View All Posts By User
peach
Bon Vivant
*****




Posts: 1428
Registered: 14-11-2008
Member Is Offline

Mood: No Mood

[*] posted on 8-4-2012 at 07:30


Teflon can't be dissolved in a solvent. The liquid teflon that's available from DuPont is a fine suspension of particles.

Most of it's major advantages as a finish are also it's disadvantages in terms of achieving that finish, in that it's not something most people are equipped to do and quite easy to mess up.

Another method of applying it is to blow tetrafluoroethylene into a vacuum chamber and then hit it with plasma to initiate the polymerisation as it comes to the surface. The surface ideally needs to be 'ultra cleaned' (with active plasma) and then plasma etched before the polymerisation.
View user's profile View All Posts By User
INORGANICUM
Harmless
*




Posts: 11
Registered: 12-3-2012
Location: United Kingdom
Member Is Offline

Mood: GOOD

[*] posted on 8-4-2012 at 13:14


plasma initiated polymerisation in a vacume chamber it is then. LOL Now thats a home made/built OTC set up id love to see.:D

I had no idea it was so complex. thanx for the info IN ORE
View user's profile View All Posts By User
Fossil
Hazard to Others
***




Posts: 131
Registered: 4-4-2012
Location: Canada
Member Is Offline

Mood: No Mood

[*] posted on 8-4-2012 at 17:51


Quote: Originally posted by Fossil  
you could try some aqua regia (sulfuric acid and nitric acid solution) to strip the teflon. I am not sure about teflon's resistance to aqua regia/ acids in general but I am led to believe that aluminium does resist AR quite well at room temperature.

I am in no way certain of this information but you could give it a shot, but since you are worried about teflon poisoning you probably don't want strong acids coming in contact with your cookware, along with everyone else.


I noticed I made a mistake as to the composition of aqua regia. Aqua Regia is not nitric and sulphuric acid, it is nitric and hydrochloric acid.

I apologise for the mistake.
View user's profile View All Posts By User
White Yeti
International Hazard
*****




Posts: 816
Registered: 20-7-2011
Location: Asperger's spectrum
Member Is Offline

Mood: delocalized

[*] posted on 10-4-2012 at 11:57


Good things come to those who wait, Teflon™ peels off all by itself if you give it a few years. It is entropically favourable for Teflon™ to peel off of cookware:), I've witnessed it first hand.

I have pots and pans with Teflon™ coatings that are about to expire. I'll see if I can peel them off or something. If you're wondering how old they are, I'd say close to 3 years, they were all bought at the same time, from the same manufacturer.




"Ja, Kalzium, das ist alles!" -Otto Loewi
View user's profile View All Posts By User
peach
Bon Vivant
*****




Posts: 1428
Registered: 14-11-2008
Member Is Offline

Mood: No Mood

[*] posted on 10-4-2012 at 14:02


Speaking on behalf on my own experiences, I've never seen Teflonium peel off - I do cook on a regular basis. It does get messed up if one uses metallic kitchen implements with the pans. It has to be wood or plastic, or it'll scratch. Once it's scratched up, those omelettes are sticking. Another issue is placing the pan straight under the cold tap from frying. And, the surface not being correctly etched / cleaned prior to PTFE application.

Didst thou witness this event on't cooker heated by flame? Or pan otherwise heated to a great temperature?

[Edited on 10-4-2012 by peach]
View user's profile View All Posts By User
White Yeti
International Hazard
*****




Posts: 816
Registered: 20-7-2011
Location: Asperger's spectrum
Member Is Offline

Mood: delocalized

[*] posted on 10-4-2012 at 15:40


Quote: Originally posted by peach  
Speaking on behalf on my own experiences, I've never seen Teflonium peel off - I do cook on a regular basis. It does get messed up if one uses metallic kitchen implements with the pans. It has to be wood or plastic, or it'll scratch.


I'll post pictures when time permits, but I have 3 or 4 pots, 2 of them have a Teflon™ layer that is eroding very badly. I wouldn't be surprised if bits of it make it into my food. Since it's incredibly inert, I'm not losing any sleep over it. I also cook on an electric stove, no flames, the highest temperature it reaches is about 400C, the melting point of zinc.

I do not use metal utensils regularly, they conduct heat all too well, wood is always my preference, although occasionally I will stir with a regular stainless steel tablespoon.

I wonder what would happen if you stirred the contents of Teflon™ coated pans with a Teflon™ coated spoon o.O
Does Teflon™ scratch Teflon™ as diamonds scratch diamonds? That is the question...

Interesting side-note, geckos have a tough time climbing on Teflon™ coated surfaces. Man vs. nature:
Man 1, Nature 0

Nice title BTW peach, it fits you in some strange way I can't quite figure out why:)




"Ja, Kalzium, das ist alles!" -Otto Loewi
View user's profile View All Posts By User

  Go To Top