From solid glass
lay ups to complex composite structures,
vacuum bagging is a technique that should,
and can, be explored by even the novice. 
The principle
behind vacuum bagging is that of using
atmospheric pressure as a tool. At sea
level, one atmosphere weighs 14.7 psi
(pounds per square inch) or 29.92 inches
of mercury. In the absence of a vacuum,
a surface has atmospheric pressure exerted
on all sides and is equal. When a vacuum
is generated on one side only, the result
is an increase of pressure on the other
side equal to the amount of vacuum being
generated. A one square foot area is
receiving 2,116.8 ponds of pressure
with a 29.92" Hg vacuum
beneath it.
Make sure all materials
are compatible with the resin system,
and that they can handle the cure temperature.
Also remember that oven or autoclave temperatures
will likely approach 375-400 F during
a 350 F cure bagging materials must
be compatible with these higher temperatures.
More
info on vacuum bagging
|