Not just an replacement, but an improvement!

Tube Base Glue
Updated: 10-Feb-2016

Description. Tube base Glue #1. Order Number: 611-007-91

We used this glue to repair a loose base of an Emission Labs tube. Since many years we glue the Emission Labs tubes now with a type of glue which can never get loose any more, but there is still interest in this old product to repair historical radio tubes. This glue can be used to repair a loose tube base, when there is still some good part of the original glue inside. The original glue will be partially solved and build a strong compound with the new glue.  It will have a very good result, and requires no cleaning of the surfaces to be glued, and does not require removal of the tube base. As long as not fully hardened, any residue can be removed with a wet cloth, so you can clean the glass and the base after repair. Once dried, this glue will not solve any more, and gets transparent. So the optical result is very nice.  

Instructions before use: 

  1. Attention: This glue is organic and may not be stored or shipped at frosty temperature.
  2. With historical tubes, printing wipes off easily, and this greatly reduces the collector’s value. To prevent this, put plastic foil over the glass, and tape this near the glass bottom.  Also tape the tube base from the side. So only the gap is left, to work on. It is much less work to prepare the tube like this, then having to clean it afterwards, and the risk damaging of the printing. 
  3. Get some strong elastic rubbers.  You will need those during the process. 
  4. Mix the glue in the bottle, using a small screwdriver or an old chop stick. The glue may look "bad", when you open the bottle, with particles inside, but what you see is normal, the particles are needed. It just needs some mixing.
  5. Inside the bottle is a small brush. With the brush, apply the glue between the base and the glass, all around the base. It is important not to use an excessive amount of glue.  
  6. Hold the tube horizontal and gently rotate the base back and forth against the glass, with many small movements, and use no force.  This will solve the original glue and the new glue will slowly creep inside the base while doing so. You will see this happening after 30 seconds, while making small movements all of the time.  Use no force while rotating the base, because otherwise the original glue breaks off.
  7. Only when the glue was completely absorbed quickly, you can repeat the above step only once. Don’t try to put as much glue inside the base as possible. 
  8. Wipe off excessive glue, but there is no need to perfectly clean it away. 
  9. Put the elastic rubbers on the tube, so the base will pressed to the glass. Some glue might be pressed out.
  10. Clean the tube with a cloth and a few drops of water on the cloth. 
  11. Rotate and adjust the base in the final position now. 
  12. Let the tube dry.  DON’t put the tube in the normal position. Keep it upside down, so no glue will leak on the pins, inside the base.  It may be useful to use a jar or a glass for that.
  13. After 10 minutes check if some glue has come out, and remove this when needed.  Now finally clean the tube.  Later, a small film of glue can be removed easily, but dried drops can’t be removed well.
  14. The drying time is two weeks.  (Sorry!) During this time the tube must be upside down, to prevent tube glue internally leaking on the electrical wires.  Don’t try after one day if the base is already fixed, because it may look ok, but may break off when you use it. So don’t try it.  Best is leave the tube untouched.
  15. Don’t put heavy force on the tube in the beginning, as the hardening will continue for some more time.
  16. Important for good result is that most of the original glue is still there. If the base breaks off again, this may happen sometimes. Reasons being simply the gap is too large. This will be solved by repeating the process as many times as needed. Eventually this will fill the gap, and the tube will be repaired. Another reason can be, the glass surface inside was too dirty. After the socket gets loose again, this dirt is now captured inside the glue, and the glass is actually shiny cleaned inside now. In this case, a second attempt will definitely glue the base.
  17. Better repeat with small amounts of glue, than try to fix it at one time with many glue.
  18. In case you have ratting pieces inside, you can often fix this without having to remove the base. In such a case, apply the glue normally, but make some more effort in solving the original glue. So you rotate the base a little longer, until you feel the gaps gets a bit wider, and it this allows you to apply a little more glue than normal. Then, when you put on the rubber bands, the excess glue will be pressed outside the gap. You can see this. This happens of course also inside the base. Then, you can try to hold the tube upside down, and shake it carefully, trying to find a position when you capture the loose pieces with the excess glue inside. Perhaps you won't be successful with the first tube you do, but when you practice with a few tubes, you will learn how to do this. This is really possible.
  19. If you are not successful capturing the loose pieces, and you definitely want them out, you need to desolder the base. Consider not doing so, but here is some advice still. A four pin base you can often remove conveniently by heat up one pin, and sort of "throw" out the liquid solder on the floor, with a fast movement. However an Octal base can not be de soldered like this, and it has also quite a risk you won't get it back on when you are not a dentist. Also desoldering is difficult. Use lots of additional flux, and a good desoldering mesh wire, but in any case, make sure the wires are loosened one by one. So you can see and feel they are loose inside the tube pin. So not try to heat them up all together, and wiggle off the base. That may stretch the wires inside, and they are sometimes nicely bended in order not to get a short. Be really careful to remember the positioning of the wires inside! Like put a mark on the glass, or anything that helps you. This will become extremely difficult if you don't know any more.
  20. After a tube base repair, the tube must be tested, for shorts and leakage. This is just to make sure no glue has dripped inside the tube base. Only if it passes this test, it can be used safely. 
  21. To prevent the a socket to break off: Never pull out a tube by the glass. Only pull by the base.

Disclaimer:. This glue may only be used by a certified Radio & TV technician. Don’t use it for any other purpose or in any other way as indicated above. We are not responsible for damage resulting directly or indirectly from the use of this glue. The glue only allows a repair ATTEMPT, it does not guarantee so. Afterwards, the tube must be tested, using a calibrated tube tester to make sure all functions are normal, and no short or leakage may be present. Only when the tube passes this test, it can be used, but any risk resulting from use, we do not accept, as this is really intended as a repair atttempt only.

Subscribe or unsubscribe our Mailing List
© EMISSION LABS . All Rights Reserved.