[ohohyodafarted]

First, I am also keeping my fingers crossed for RACS to be successful.

I don't know anything about frit glass, but I can tell you that our epoxy will seal vacuum leaks and it will also stand the temperature of 600 degrees F, for 6 hours in the evacuation oven without any degradation what so ever. It bonds to glass so well that the only way to remove it is to GRIND it off.

IN our experiments we found that a THICK layer of our high temp high vacuum epoxy became brittle and was subject to cracking. The tube will be flexing at the ultor ring when a vacuum is applied. We have since changed our epoxy protocol to painting a thin layer on the ultor ring in hopes that it will be more compliant to the flexing of the ultor ring when subjected to the vacuum.

To Eric:

Your assumption would be true for a dud 15G tube that is still under vacuum prior to the rebuilding process. We now believe that even an under vacuum 15G must be put through a sealing process prior to rebuild to prevent what happened to our first successfull rebuild. And yes, if we had even sealed the tube after we rebuilt it (which we did not think we needed to do) we would probably still have a working tube today.

However, for 15G that is full of air, it is unlikely that the leak would be small enough to give you enough time to seal the tube post evacuation. It would be a crap shoot at best. Sometimes it might work and other times it would be a total bust, if the leak rate was to big.

Presently working on the PowerPoint presentation for the ETF. So far I am up to 100 slides and counting. Better take some NO-DOZE, this one is going to be rather lengthy.

Bob