Uncle Al wrote:
Tomasso wrote:

"Zak" wrote:

The ceramic end on the 500W bulb in my quartz halogen floodlight has
cracked.

I have repaired it with Araldite Rapid.

Will the temperature of the bulb be too much for the adhesive?

I have a feeling that Araldite can not be used at very high temps but
can't find a Google reference which gives any real information

You could also use Duct Tape (Gaffer Tape) - the high temp version. :-).

I do recall a high temp "dope" for sealing up vacuum system (OK to about
10^-5 Torr, I think). Sealed holes in glass and was flexible enough to
handle temp variations without losing seal.

Can't remember what it was called.


Glyptal thermoset resin (phtalic anhydride, glycerin, red pigment...).

You are showing your age. Glyptal went out about 1970. The two
sealants of choice are Torr-Seal (Varian) or equivalent, an epoxy which
goes to 10^-9 Torr and ~ 120 C, or silicone based resins that you can
use (with luck) to 450 C The former have structural strength. The
latter are strictly paint on and the replacements for glyptal (I
remember glyptol, but that could be age).

josh halpern