Vacuum bagging is a common method of building fiberglass or Kevlar composite boats. It is conceivably workable for strip-built or stitch and glue boats, but I've not heard of anyone who has done it. I recently purchased a good vacuum pump of Ebay and may try something in the future. The potential problems are many, and the cost of failure is a lot of work down the drain. Try a lot of experiments first, but it should be possible.

: Has anyone tried vacuum bagging to reduce weight? It is used in Model
: Airplane construction. It reduces epoxy loads and make a smoother finish,
: so less fill. I know you had to be careful to maintain the desired shape
: from warping. Not sure if it would work well on a kayak form.

: I can't remember what was used for the seperation skin. I'll have to dig some
: detail up. But as I recall it is not that expensive. And the vacuum pump
: does not have to be and bigger to do larger forms.