On Mon, 14 May 2012 22:28:13 -0400, "Existential Angst"
wrote:

Iffin you REALLY wanted to be sure that a nut won't fall off a screw, or a
screw will loosen, wouldn't plain ole 2-part epoxy be the best bet?

There are epoxy thread-lockers made for volume production. They're
hollow phenolic beads, half of them filled with resin and half of them
with hardener. The threads are dipped in a weak adhesive and then in
the beads, whereupon they can be stored for as long as you want. When
you tighten the nut the beads crush, the epoxy and hardener mix, and
the mess hardens.

For non-production use, Loctite is much more convenient.


Also, if an epoxied screw/nut did have to come off, wouldn't a little heat
do it?

A fair amount of heat. And the epoxy doesn't melt. It may get soft,
but it chars.

Five-minute epoxies can handle less heat than the slow-cure types.

--
Ed Huntress