Thanks i'll look into devcon..

the cyano/silicon mix is recomended by the manufacturers but once I have done this, they always return to my workshop as they unstick in a few months.....

The 5600k measurement relates to the colour AND the temperature, however it is only the temperature of the source of light, in this case the gas. Eg in normal fillament bulbs, the fillament is around 3200K but the glass does not reach anywhere near that!
9
The temp where these diacroics is definately nowhere near that range, as there is a protective glass between the bulb and them, (for heat and UV light prevention)


I'm currently trying to beg/borrow/steal an electric theremomiter suitable to measure and so, have a better Idea of what I can use......