[Username1]

for what its worth II, If a vacuum is generated in a system not leaking and holds, then the pump is only running a short time each week, to deep vacuum what is coming from the tube. Heat need not be constant, but possibly only a few hours at a time since you would be aiding what the vacuum pump is doing. Lets say you sat it out in the sun each day and did it only in the summer, so 6 months not a full year. Or built a solar hot box, build more heat than just sitting in a sunny spot. My solar panels easily put out over 115 in the summer when they are much less efficient. You would only need to supply a small amount of additional heat, possibly a 100w light bulb or two's worth.

I reclaimed an open to the atmosphere 3 ton A/C unit and vacuumed it down to where my gauge didn't even begin to register daily for a few days during the hot summer days so the heat of the day would aid in removing the moisture from inside the unit. After a week I had it down to less than 200 microns and held since.

Seems to reason, with a leaking tube but still getting some emissions, you may have something that can be reversed, and recovered, if the idea were given a test.

Since the 15G Has a unique problem of slow leaking, then restoration of vacuum would need to be done slowly over time. If it works, then you also have a few hours to coat it with a known sealer.

200 degrees is achievable and much safer than much higher temps.

I would imagine since the tube has not just been rebuilt, then removal of some materials that would vaporize at higher temps would not be necessary, it would just need removal of standard atmospheric elements. Like water vapor.

Imagine if it could be done and worked...... A few 15g's out there in this condition..... No face cracking chance..... complete implosion........

The worst thing you might need to do then, which I would try instead of a rejuvenation attempt, especially since it involves raising the heater voltage, which by the way heaters exposed to higher voltage in a less than perfect vacuum will surely fry, the thing to try would be reactivating the getters with one of those rf getter coils and see if you can use that to take care of anything left in the tube that needs gettin'