I can't imagine why they used a conduit in that application to begin with.
I'd just remove it. OR take some great stuff, stick the nozzle in the pipe,
wrap a rag around it, and pull the trigger until it comes out the other end.
Now you'll have to find another something to fret about.

--
Steve Barker

YOU should be the one
controlling YOUR car.
Check out:
www.lightsout.org




"Edge" wrote in message
oups.com...
I have a two story house with an attic. The attic has a bare bulb
utility light that is wired using EMT metal conduit. The conduit rises
about three feet above the attic insulation. The conduit runs straight
down through a wall to an outlet box on the second floor. I have
noticed water in the outlet box in the winter (Midwest). Warm moist
air is going up the conduit, condensing in the cold of the attic and
running back down to the outlet box. The conduit and metal box are
rusting along with the potential problem of shorts from the water. I
have tried to stop the air infiltration by using foam cutouts behind
the outlet cover. This has helped some but does not stop it
completely. I want to know if it is safe to caulk the conduit openings
either at the second floor end or the attic end. I worry that blocking
the second floor end might be trapping moisture in the conduit. Will
blocking the attic end cause heat buildup? Can another material be
used instead of caulk, like fiberglass? What does the electric code
say about this situation.