Cooking For Engineers

[miss chief]

OK. I'm confused. Can someone confirm, deny, or clarify the following info?

1. Anodization of a pan creates an Al Oxide coating that prevents Al from leaking into the food. True or False?

2. The Al Oxide coating from the anodization process is non-stick? True or False.

3. Manufacturers of pans add non-stick coatings to their hard anodized pans. (Ex. Circulon has an Autograph coating by DuPont.) True or False?
-- Or is Autograph just a proprietary way of doing the anodization process - meaning the coating consists mainly of Al Oxide (and the dyes)?

I suppose my main question is, "what is in the coatings of pans labeled 'hard-anodized' ?"

And, which substance of the coating makes it non-stick? The Al Oxide? Or 3rd party coatings?

--- Also, Circulon sometimes lists "hard-anodized Aluminum" and other times it lists "hard-anodized construction". Does that mean you can anodize something other than Al? An alloy perhaps?

Thanks,
mc

[Dilbert]

well, true is: it's mostly marketing hype.

if you dip alum into a weak sulfuric acid solution, it'll turn black - that's anodizing. the chemicals formed in the coating are semi-protective against corrosion.

hard anodizing is slightly different chemically - and the resulting coating is harder to scratch thru.

I wouldn't say hard anodized is "non-stick" - perhaps "less stick" - but not on the order of "non-stick"

as for absorbing aluminum in the diet, that aluminum causes/contributes to dementia / Alzheimer, that has been rather thoroughly debunked. it was once a doctor's theory - it's since proven inaccurate. see Alz.org for info.

you'll also find that one absorbs more aluminum from toothpaste, deodorants and pickles (yup!) than a alum pan could remotely provide.

hard anodizes looks prettier and will "wear" better, that's about it.

>>anodize something other than aluminum?
yup. lots of stuff. we have our mild steel parts anodized for a bit of rust resistance, looks snappier too....

[Hexis]

I like wiki's description a lot:

Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts.

It's used a lot on Al parts, some other materials have processes. I have done some (hobby style) Al and Ti parts. There are different types, some dyable to take color, others not. It's not so much a coating as a hardened layer of the metal itself. The process does add a nominal amount of material to the surface, but it's not a coating that can flake off or anything. The "hard anodizing" advertised is really just a thicker layer than "normal".

Acids can dissolve the oxide layer, so it's not dishwasher safe. I personally prefer stainless clad cookware (or cast iron for what it's good at).