[ars]

I didn't do math. I did an experiment.

I took two identical pieces of metal. Dried one in a warm stove the other on a table.

The one on a table had no visible rust. The one in a stove was completely orange.

[learc83]

I don't doubt that warm metal rusts faster, just how much faster.

There's a pretty big difference between drying something in a warm stove vs applying a direct flame to it on the stove top.

It takes just a few minutes to get the skillet hot enough where the water pretty much instantly evaporates. I'd imagine putting it in a warm stove took much longer to completely dry it.

[ars]

Direct flame would be even worse. It will rust much faster than it will evaporate.

Reaction speed doubles for every 10 degrees F, but evaporation doesn't.

[learc83]

Reaction speed doubles for every 10 degrees F.

That can't possibly be correct, or at least it's only correct over part of the range.

If a pan rusts at a given rate at 70F, it would rust at 2^33 times that at 400F--those numbers just don't work at all.

Also once the pan heats past the boiling point of water, there is a huge decrease in drying time.

[lkbm]

If my cast iron can rust from two minutes on the stove, I need to stop cooking wet foods in it. It has yet to be a problem, though.

[ars]

Of course. But that isn't what I said.

What I said was that if you are heating the iron in order to speed up evaporation to avoid rust, you are being counter productive. You will avoid more rust (if any would be formed in the fist place), by just letting it air dry.

[lkbm]

I don't know what you said, then. People are saying we put our cast iron on the burner for a couple minutes to dry it off and you're saying the direct flame will cause it to rust.

[andrewflnr]

In my house, we stove-dry pans constantly, precisely to prevent rust, and we never get any. It's not intentionally an "experiment", but it's enough to make me think there's an issue with your methodology.

[ars]

You probably would not get rust anyway, so stove drying isn't hurting anything much.

But it's certainly not helping.

The methodology was not complicated: I washed some porous/rough metal under the faucet, dried it with a paper towel, then put one piece in the oven at 170F, one on the table.

[learc83]

170 is below the boiling point of water, it may speed up evaporation but it won't boil off.

300-400 (what you'd get from the stove top) is above the boiling point, so the water rapidly boils off.

These 2 things aren't comparable.