Anyone ever tried making a mirror blank from an old flat screen CRT?

[Norlesh]

Have been playing around with some old CRT tubes this weekend [attempting to separate the cone from the face in order to make a vacuum bell jar - anyone know a way of softening the adhesive they use?] and it occurred to me that a big old flat screen front glass would have all the necessary thickness to cut out a nice sized mirror blank.

Anybody tried it? any glaring reasons why it would be a bad idea? From what I've read the cone is usually made from flint glass (~20% lead), while the front is barium glass.

While it's not Pyrex, it would pretty much be free in most cases.

[Norlesh]

FYI - turns out to separate the front plate from the tube when recycling CRT glass they wrap a length of nichrome wire around the lip where the two surfaces are joined and rapidly heat the wire with a current and then cool it with compressed air to create a thermal shock that cracks the adhesive without breaking any glass (on a good day).