15-06-2011, 03:05 PM
Just for clarification
"The January 2003 issue of the excellent American magazine 'Antique Radio Classified' contains two letters warning about the dangers of using cyanoacrylate glue, with trade names such as Super Glue, for repairing valves.
Restorers often need a fast-curing glue for cementing loose glass into valve bases but danger lurks here. The problem is the difference in the coefficient of expansion of glass and of the cyanoacrylate will cause the glue to act like a hot wire glass cutter - cleanly cutting the glass off at the base when the valve heats up to full operating temperature.
The bottom line is never use this glue on any valve or tube that runs too hot (when up to full temperature) to hold your hand on the tube. This means no power output valves and no rectifiers. However, this glue is considered safe, with some reservations, for battery valves and most small signal valves, if they don't get too hot."
I would just avoid it at all costs, even on battery valves, it's unforgiving too when manipulating. Araldite gives you time to position secure and remove excess with the appropriate cleanser.
The recommendation for Araldite came from a very well know TV engineer in West Sussex.
"The January 2003 issue of the excellent American magazine 'Antique Radio Classified' contains two letters warning about the dangers of using cyanoacrylate glue, with trade names such as Super Glue, for repairing valves.
Restorers often need a fast-curing glue for cementing loose glass into valve bases but danger lurks here. The problem is the difference in the coefficient of expansion of glass and of the cyanoacrylate will cause the glue to act like a hot wire glass cutter - cleanly cutting the glass off at the base when the valve heats up to full operating temperature.
The bottom line is never use this glue on any valve or tube that runs too hot (when up to full temperature) to hold your hand on the tube. This means no power output valves and no rectifiers. However, this glue is considered safe, with some reservations, for battery valves and most small signal valves, if they don't get too hot."
I would just avoid it at all costs, even on battery valves, it's unforgiving too when manipulating. Araldite gives you time to position secure and remove excess with the appropriate cleanser.
The recommendation for Araldite came from a very well know TV engineer in West Sussex.
