Vacuum Bagging

In vacuum bagging a sheet of film like material is placed over the mold and sealed at the edges with a special tape. This is the “bag”. Then the air is sucked out from under the bag by a vacuum pump. That’s the “vacuum”. Air pressure pushes down on the bag at about 14psi at sea level. That equates to one ton of clamping pressure per square foot. This vacuum induced pressure forces out trapped air bubbles and voids. This increases the strength of the part because micro fractures will start in a void or bubble. These fractures are the beginning of fatigue and possible failure under stress. Vacuum bagging prevents that from starting and also makes sure that the core and layers of fabric are in full contact.

This shows a vacuum bag being fitted to our 35 LT hull mold.

Revenge 35 LT hull vacuum bag