[maxhifi]

What Tom said.

I put the tube face up in a plastic garbage can, and covered it in a black plastic garbage bag to let it get warm in the sun, for a few hours. Then, I removed the garbage bag, and used a guitar string, wirh a handle on either end made from a length of dowel, to saw through the silicone, starting from one corner and working my way to the opposite corner. I had a few strings snap on me, make sure you have some spares.

Removing the silicone takes a mix of elbow grease, frustration, acetone, alcohol, plastic scrapers, finger nails, and every other solvent I could find, along with hours of scrubbing. The really deteriorated stuff comes off easy but the inside part was about like cleaning half a pound of butter burned on to the bottom of a stainless steel saucepan.

Then I used four pieces of foam tape to elevate the safety glass off the tube, and then caulked around the edge with clear caulking.

During the whole process, I wore thick coveralls, and a full face shield, with particular attention given to protecting my neck. Speaking of necks, never lift the crt by its neck or apply any pressure to it.

The result was excellent and I would do this job again, but be aware it's a pretty major job which has some risk associated with it, and you shouldn't forget that it the tube legs go, it could be fatal if you don't take every possible precaution.