Neck-Thru Construction (part 3)

      Alpha, Bamboo, Carbon Fiber, Construction

Wrapping the Neck-Thru

This installment concludes the Neck-thru construction series. As a final step, the neck is wrapped in 4 layers of carbon fiber to ensure maximum rigidity. We vacuum bag the whole thing to ensure that there are no air-pockets and bubbles and to make the carbon fiber layup hug the shape as tightly as possible while allowing the resin to cure.

Vacuum Bagging

Vacuum bagging is a method that uses atmospheric pressure to hold laminated components (laminating epoxy and carbon fiber) in place until the adhesive cures. Laminated components are sealed in an airtight bag. Atmospheric pressure exerts around 101 kPa (14.7 PSI) inside and outside the bag. A vacuum pump then evacuates air from the inside the bag reducing the pressure inside the bag. This negative pressure creates as much as 82 kPa (12 PSI) pressure differential that compacts the laminate resulting in excellent consolidation and interlaminar bonds. The vacuum also draws out trapped air (air-pockets and bubbles).

Vacuum bagging is a crucial step. I’ll provide some links below detailing the process.

Laying-up the first carbon fiber layer

Laminating epoxy applied in between layers

Yet more layers of carbon fiber

Vacuum bagging the whole thing

Excess resin being drawn out by negative pressure

The carbon-fiber wrap ends at the neck-body heel

Perfection! The Final Result

(Click to zoom)

Perfect!

Further Reading

  1. Basic Vacuum Bagging
  2. Vacuum Bagging: Basics
  3. Vacuum Bagging Techniques
  4. Vacuum Bagging Equipment and Techniques for Room-Temp Applications
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