Norminn wrote:

clipped

Don't know how the oil film would hold up. Only a rust through would let
microwaves out. Cheap for a basic unit, not so cheap if used as an
excuse to upgrade to an Advantium or similar. Of course the old unit
could migrate to the workshop for reheating coffee while working on a
project.


I started a fire in my microwave once, thawing a loaf of bread and had
forgotten to take off the
metal twist tie. My son asked, "What's burning?" I said, "What do you
mean?" He pointed at
the microwave and the flaming bread wrapper. Very small amount of
flame, and no damage done.
So, that leads me to ask about exposed metal inside the mw.....dangerous?

Not if used properly. In the early days of microwave ovens they simply
said not to use metal in the microwave, assuming (possibly correctly for
the time) that consumers were not sophisticated enough to understand the
actual restrictions on using metal in a microwave. More recent microwave
oven user manuals and microwave cookbooks give the real instructions,
which mostly amount to: No sharp points and not too close to the oven
walls. I readily use stainless bowls in the microwave and leave spoons
in containers in the microwave without issues. Microwave instructions
and cookbooks also tell you to use aluminum foil to shield thin areas on
foods from overcooking. Your metal twist tie violated the "no sharp
points" rule, concentrated the energy and caused arcing which started
your fire.