21fjp22 safety glass

[timmy]

Is it really a huge issue to put the safety glass on the 21 inch round tube or is this a definite no and yes I broke mine heated it so hot that I was worried the tube would implode and the glass still didn’t budge.

[Electronic M]

I try to put it back on whenever I can get a decent one. (I've got some scratched ones someone could try polishing the scratches out of.)

On RCA style moldy white cataracts I've found you need to get the entire face up to ~170f for the glue to let go. That's only safe if done over several hours. I try to wait for an over 80f day (the farther over the better) keep the tube in the garage from the night before so it's outdoor temperature by the time I put it in the sun. Let it sit in the sun till it won't get hotter then I take a 250W incandescent heat lamp place it above the tube so it heats the whole face evenly and wait another hour or two. You want the entire tube to GRADUALLY get to 145f+ (the higher the better) before you break out the heat gun then you get it the rest of the way with the gun.
They bake these tubes much hotter during the vacuum pumping stage of manufacturing the reason they don't pop in manufacturing is the SLOWLY EVENLY heat the entire tube. Too fast or uneven is when they pop.