Can the glass on a tube be repaired???

I saw it on Ebay, a Krazy Glue Nos tube repair kit.

This is pretty simple, if the glass is broken and you can put your finger inside the that 6SN7 tube. The tube is a goner

Check this tube making video out.LINK>>[http://www.mullardtubes.com/Video.aspx]

I watched the video. It was fascinating it. How did he evacuate the tube to create a vacuum? If it was there, I missed it?

Wendell

There are some glass audio tube repair services, you can try contacting them. Here's the website:
http://hotglassaudio.com/home.htm

Fortunately Bigkidz, there are a more than a few good NOS 6NS7's still
around but, I'm sorry to hear that. Do you now need to get a matched pair? So
many times if you don't, the mismatch sonically is too apparent in lots of
gear, even after biasing. Something that may make this mishap sting even a
bit more. Sorry

Nice video Albert... Reminds me of time gone by watching my grand father
making crystal radios for my brother and I and watching my father (fine watch
maker and gunsmith) machine and fit custom watch gears and staffs and his
father making wood furniture with detailed marquetry, all great craftsmen. My
have we lost some of these rare talents in a generation or two.

Happy Listening!

Sorry to hear this! If the vacuum hadn't been lost, there would be no issue.

It'd strictly be cosmetic, but if the glass is broken in a way that would present a safety problem for those in the home, you would have wanted to address that.

When I was a chemist, I was incredibly lucky to have been trained by someone from the former Soviet Bloc, which meant he was old school (not what people mean when they say "old school" today, I mean REAL old school) and practical. So, we were constantly making and modifying a lot of our own lab glassware to suit whatever task was in front of us.

In case anyone else needs to do something along those lines with a vacuum tube, fire up a propane torch, and with a large and sturdy pair of tweezers, put the tip of the tube in the flame. Obviously, your hands will soon tell you if you need to use a glove or not (get a big enough pair of tweezers, and you won't), sacrificing dexterity in order to keep a hold of the tweezers. When the glass begins to liquefy, use the tweezers to pull the glass together into a point, stand the tube up, and let the point fall down on itself. It's like making taffy for anyone who has worked with molten candy. You can also do this to take a dangerous edge off something that's broken around the house that you really don't want to throw away for whatever reason, as the resulting edge is smooth and safe like the edge of a dinner plate or drinking glass. A while back, I discovered this is the way it's done in the tube factories, as it was exactly the same kind of work (chemists and engineers making their own glassware to suit their particular need that day), and my thoughts took me back to an earlier and very happy time in my life.

Of course, like anything else, you need to get the hang of it, so practicing on one or two trash tubes would be a good idea.

Worse yet it could have been a NOS Western Electric 300B.

Thanks for the replies. The top of the tube, the glass is broken so you can put you little finger into it. Yeah rare 6SN7 tube go figure it would be the one that fell.

What do you mean by "the top of the glass"?? If it is the external glass "point" on the top of the tube then the vacuum may be intact. If the glass body of the tube is cracked or broken then the tube will not work.

1.No
2.See #1.

Maybe if it's rare enough might be worth searching for this guy:

http://news.cnet.com/8301-13645_3-9843011-47.html

What GMC and Narrod posted is correct, the tube is destroyed unless the glass can be remade and vacuum restored. Unless the tube is so rare it merits that I would keep it as a conversation piece or throw it away.

No. It is a "vacuum tube". Without the vacuum the tube is destroyed.

if the vacuum is lost, i would venture that the tube is shot.