Actually, vacuum bagging is not related to the process of the glass being hand laid or not. You can hand lay (simple to understand) the glass, or you can shoot it in with a chopper gun. I would call resin infusion "hand laid" as it requires careful positioning of the glass layers by hand.

Vacuum bagging is a process that holds the glass in place as the resin cures. You can use a hand squeegee to work the glass and resin till it sets up or you can put the mold in a bag and turn on a vacuum. The squeegee can be good at removing more excess resin, but the vacuum bagging is less labor. The vacuum bagging is required on our foam core layup as it forces the foam to adhere to a concave surface.

Our glass process is:

- Gel coat sprayed into the mold.
- 1 st layup is hand layed glass and resin worked with a squeegee. Cured.
- Foam core is laminated in place and vacuum bagged till cured.
- 2 nd layup (hulls inner layer) is hand laid and worked with squeegee.

We do not use the vacuum bagging on the second layup because it can shift the glass and cause wrinkles. Not good for the structure.