Vacuume pressure

[Wooden Affairs]

I am a sheet metal mechanic for helicopters and we use a vacuum with some of our composite repairs. It combines vacuum and pressure in one shot. We pull about 25 in/Hg to apply even pressure and remove air bubbles. The bagging method we use allows complex shapes to be safely accommodated and is very adaptable.
Here is my question. What kid of pressure is 25 inches of mercury? I realize that is a measurement for vacuum but the bag is squeezing both side of 2 pieces of metal. If one was to have a finger between them I guarantee the will be pressure going on. I have asked many people this question and still do not have a good answer.

 

[DSurette]

Not sure if this is what you are looking for, but an online converter shows that 25 inches of mercury is about 12.28 pounds per sq inch.

 

[Wooden Affairs]

Not quite the kind I pressure I was expecting, but I believe it. The system works wonders on fiberglass and other resins.