0
$\begingroup$

Like a million others, I have a set of enameled cookware that has seen enough use that the enamel has boiled, burned, or chipped off down to the cast iron substrate. Surprisingly, the outer painted surface that takes direct fire is undamaged. It seems reasonable, then, that removing the inner enamel coat mechanically (grind or blast or peen) and applying a hard, high temperature coating (engine enamel or powder coat) would restore the finish and allow me to continue cooking/frying on the cookware. It seems a simple solution that can be done in any home back yard. However, the obvious question is whether the new coating would off-gas food-borne toxins into the food when heated.

I've searched many "Maker" websites and even asked a Major Manufacturer of one of the coatings and every answer I've gotten is, "Uh, I dunno. So maybe not."

Is it safe to cook/fry/bake/boil food safely on a painted surface?

(and you guys thought this wasn't a technical question)

$\endgroup$
5
  • 1
    $\begingroup$ 1) You are talking about either engine enamel, poweder coat or high temeprature paint. I don't think these three things are the same. Which is it? 2)Have you tried sourcing kitchenware enamel powder? $\endgroup$ – mart Oct 23 '20 at 5:28
  • $\begingroup$ Is there any reason to suspect that the cast iron contains toxic dopants or impurities? Or does the topography of the worn surface make it impossible to clean effectively so that it will harbour dangerous microbes? If not, why not just leave it as it is and keep cooking? $\endgroup$ – Daniel Hatton Oct 24 '20 at 14:27
  • $\begingroup$ @mart - Any of the three (but not silicone - no wear resistance). Tried to find kitchenware enamel powder, but what I got was either fused ceramic (1600F + kiln temp to fuse) or powder coat for the exterior of pots. Not cooking surface. $\endgroup$ – Mike Havnaer Oct 27 '20 at 0:08
  • $\begingroup$ @Daniel Hatton - Certainly the cast iron might contain toxic impurities, but the manufacturer made it specifically to eat off and it is coated so the iron isn't exposed to food, anyway (LeCreuset pots have exposed iron rims that could touch food, so I doubt they'd make it poison). Cleaning the existing surface harbors no more toxic microbes than cleaning a cast iron skillet and the microbes will likely be killed by cooking temperatures (unless you're doing it wrong). But the ceramic coating continues to flake off, leaving occasional sandy grit in the food. Harmless, but, icky. $\endgroup$ – Mike Havnaer Oct 27 '20 at 0:21
  • $\begingroup$ Yeah, the "sandy grit" thing doesn't sound very nice. $\endgroup$ – Daniel Hatton Oct 27 '20 at 10:46
3
$\begingroup$

I wouldn't try for my kitchenware. I would strongly advice against it.

The main problem is that you'd be in danger of digesting high temperature paint. Even though some of them might be inert, we'd all be better without them in our system.

In order for this to work you'd need to make sure the following things (which are near impossible if you are not - or have been - in the business):

  1. that there is good adhesion between kitchenware and the substrate material.

However, in most cases that means pretreating the kitchenware surface (mechanically, thermally and/or chemically), and using specific products for the enamel.

  1. The enamel surface is even. Any lump or crevice would make the enamel prone to be mechanically detached, when for example you would stir something in the kitchenware.
$\endgroup$
2
  • $\begingroup$ Once the manufacturer's ceramic coating fails, the coating flakes off slowly so that a harmless but unappetizing grit finds it way into food - inert, but we'd all be better without it in our system. $\endgroup$ – Mike Havnaer Oct 27 '20 at 0:27
  • $\begingroup$ (sorry, edit cut me off) Naturally, the pot would have to be prepped by sand-blasting away all the original coating ($189 for a booth at Harbor Freight), then cleaned with a flash-off cleaner (rubbing alcohol) before the coating is applied so that the surface is smooth. The mystery is whether and what chemicals are in the coating and what is the most inert one to choose? $\endgroup$ – Mike Havnaer Oct 27 '20 at 0:35
2
$\begingroup$

The coatings on cookware are not paint. They are fused ceramics.

$\endgroup$
3
  • $\begingroup$ Interesting. How hot do you need to get to fuse ceramics? $\endgroup$ – jko Oct 23 '20 at 14:38
  • $\begingroup$ A wide possible range ; the only one I did was about 1600F but that was for a special industrial application. $\endgroup$ – blacksmith37 Oct 24 '20 at 0:59
  • 1
    $\begingroup$ Right. So what do I use to replace the ceramic coating? A 1600F kiln costs several $1000 in order to repair a $300 pot. And that temperature might burn off the paint on the outside of the pot, requiring additional repair. Surely there must be some technical improvements in coatings since the 17th Century? $\endgroup$ – Mike Havnaer Oct 27 '20 at 0:39
0
$\begingroup$

I think the key here is food safety.

You would need to find a paint that is advertised as being safe for direct food contact at high temperatures. You can't really test this yourself so they need to say it explicitly.

Then you would need to find their application instructions and follow them to the letter.

I don't know of any such product, but it might exist.

$\endgroup$
-2
$\begingroup$

Every high T paint I used on exhaust manifolds failed, so no.

$\endgroup$
3
  • $\begingroup$ So the downvoter suggests that it will be safe, good luck. $\endgroup$ – Solar Mike Oct 23 '20 at 7:37
  • 4
    $\begingroup$ I'm not the down voter but with the lack of detail, this answer is more of a comment. Someone else has flagged this as a Low Quality Post, which is why I'm looking at it during Review. I don't know how I can edit this to improve it, so do I Skip this, Delete it or just hit the Looks OK tab? Maybe I should hit the Looks OK tab in the hope that you elaborate further with this answer. $\endgroup$ – Fred Oct 23 '20 at 8:14
  • 1
    $\begingroup$ Any paint will fail if the surface isn't prepped properly and exhaust manifolds run at 1200F+ ; much higher than cookware (probably no more than 700F). Wear resistance is important, of course, so silicone coating is probably not effective. Any idea what toxins are in HT paint or powder coat? $\endgroup$ – Mike Havnaer Oct 27 '20 at 0:43

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.