3120 RTV is rated for use up to 572F, and would impart some shock dampening. Do you know the actual temperature?
http://www.dowcorning.com/DataFiles/090007b58012f19f.pdf
There are some MasterBond products that are 600F and one up to 1500F:
http://www.masterbond.com/sg/htsg.pdf
Cerambond:
Ceramabond? 835 bonds halogen bulb.
Ceramabond? 503 bonds Pt/40Rh heater wire on an alumina
core. This assembly is part of a hi-temp process furnace used aboard the space shuttle.
New Ceramabond 671 Bonds Metals and Ceramics at High Temps
SUMMARYCeramabond? 671, a new high temperature ceramic adhesive developed by Aremco Products, Inc., is now used in the assembly of high temperature thermocouple housings used in furnace, boiler and stack applications to 3200°F (1760°C).
FEATURES
Ceramabond? 671 is a single part, water-dispersible, aluminum oxide based adhesive and coating system that offers exceptional mechanical and electrical properties to 3200°F (1760°C). Physical properties include torque strength of 24.0 ft-lbs, dielectric strength of 250 volts per mil at room temperature, and a coefficient of thermal expansion (CTE) of 4.1 in/in/°F x 10-6
New Ceramabond 671 Bonds Metals and Ceramics at High Temps
SUMMARYCeramabond? 671, a new high temperature ceramic adhesive developed by Aremco Products, Inc., is now used in the assembly of high temperature thermocouple housings used in furnace, boiler and stack applications to 3200°F (1760°C).
FEATURES
Ceramabond? 671 is a single part, water-dispersible, aluminum oxide based adhesive and coating system that offers exceptional mechanical and electrical properties to 3200°F (1760°C). Physical properties include torque strength of 24.0 ft-lbs, dielectric strength of 250 volts per mil at room temperature, and a coefficient of thermal expansion (CTE) of 4.1 in/in/°F x 10-6
http://www.aremco.com/adhesives-and-sealants.html
Oh, forgot to mention, alot of companies offer sample packages...