Please remember that as Dow-Corning RTV-781 cures it releases
Acetic-Acid.  Acetic-acid is corrosive to zinc, lead and copper
families of metals.  This could mean that if you have anything
from "organ pipes" to tubing, brasses or bronzes or electronics
parts, they are being exposed to increased levels of environmental
corrosion.  If that is not what you intend, maybe you should pick
a different RTV.

By the way, Titebond is a PVA, not a PVC-E.  (If I missed that
corrective, sorry.)

Wm. G. Chapman
West Point, New York