On 1/14/2017 6:11 PM, Andrew Gabriel wrote:
In article . com,
dennis@home writes:
I think the only stainless that rusts in common use is for saucepans so
that they work on induction hobs.
It appears its quite expensive to make rust proof and magnetic.
Some better pans have three layers so the magnetic stainless is wrapped
in rust proof stainless.

The alloy pans I have have a steel base fitted but they don't work as
well as the three layer stainless ones do. You can boil water quicker in
the better ones so there must be something restricting the power input
on the alloy pans.

Making pan bases is an interesting challenge.

Stainless steel is a nice finish, but it's a poor heat conductor which
can lead to uneven heating and hot spots with many types of hob, and
it doesn't work well (or in some cases, at all) with induction hobs.

Aluminium is a very good heat conductor for even heat with no hot spots,
but is not a good surface finish (unless teflon coated or similar), and
won't work with induction hobs.

Copper - same as for aluminium, but no use as a surface finish.

Iron/steel is good for picking up heat from induction hobs, but is not
a good heat conductor, so it needs a thick/heavy base or you will get
hot spots, and not good as a finish so has to be enamaled.

Since none of them is good in all cases, good pans are forced to have
multi-layer bases - typically stainless steel inside surface (or teflon
coated aluminium), with an aluminium or copper heat spreader on the base,
and for induction hobs, a steal layer to pick up the induction heating.
The layers, which expand differently when heated, need to be well bonded
to conduct heat through. (They do occasionally come apart.)


Can't beat the traditional heavy copper pan with a tinned inside! They
don't come apart. (No good for induction, I guess).

Coatings have got very much better, though. I have a lovely big cast
aluminium pan from Lidl, with a (so far) very tough coating. A third of
the weight of Le Creuset, and much quicker and more even heating, no
problem with burning.