"Thomas Cormen" wrote in message
.. .

Where the grease hit the foil, it burned and the foil stuck to the
bottom of the oven. I removed what I could of the foil, but there are
several patches of stuck, burned-on foil. We tried running a
self-clean cycle, but that did not burn off the stuck foil.

Any suggestions as to how to remove the burned-on foil without
damaging the enamel surface on the bottom of the oven?

The self-clean cycle of a self-cleaning oven is
hotter than any cooking routine: so you may
have brazed the foil permanently to the enamel.
There was a reason why your oven's instructions
recommended against the use of alum. foil as
a liner on the enameled metal.

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)