I must preface this entry with a citation for a homespun vacuum source that saved my bacon in this exercise. DrCrash
has a great
solution using nothing more than a hardware store bicycle pump for this project, as there was no way I'd encumber my little apartment with an unwieldy electrical unit.
Vacuum bagging is a commonly used technique in composites, and for good reason. When done correctly, your part will have a nice, uniformly distributed compression about the surface of the layup. This in turn helps to minimize any voids
(e.g. bubbles and wrinkles) in the buildup of layers. Also, when used with a porous substrate made of peel-ply
as we'll see, it assists in having the optimal ratio of resin to reinforcement
(e.g fiberglass, or carbon fiber, or Kevlar) by squeezing out the excess.
The project is quite simple for illustrative purposes. I'm making a small container from a mold of a nice tea container lid. I'll go over the steps to make this part, but the vacuum bagging phase is what this topic is about, so we'll be delving into that a bit more thoroughly.
First, a few suppliers that I've had quite good success with:Fibreglast dot com
- Lots of supplies for the intrepid.Aerospace Composite Products
- They also had the check valve and bag attachment and 1/4" neoprene tubing used in DrCrash's vacuum tool, and very personable customer service.Tap Plastics
While they don't have much for vacuum bagging, it's still a worth while source to mention with all their instructional material and from my experience, good staff.USPlastics
Is also well known supplier.
Both TapPlastics and Fiberglast have some very good instructional material that is invaluable for someone learning about new techniques.