Skip to content

Vacuum Bagging Carbon - V2 - Edge-Sealed Bagging

Concept

Goal

To enable vacuum bagging of larger parts by sealing a cut vacuum bag directly to the laminating base using butyl tape, while achieving a controlled and measurable vacuum level.

Specifications / Dimensions

  • Suitable for medium to large parts (size limited only by base and bag film availability)
  • Target vacuum level: ~80% atmospheric pressure
  • Requires a rigid, smooth laminating base for edge sealing

Time needed

Type Hours
Implementation 0.75 h
Waiting 0 h

Bill of Materials

Material Quantity Unit Cost Line Cost
Vacuum Bagging Kit
Reusable Manual pump with heavy-duty storage bags for low-cost vacuum pulls
1 kit £9.00 per kit £9.00
Butyl Sealing Tape
Consumable Continuous bead around the laminating base
0.4 15 m roll (12 mm) £6.50 per 15 m roll (12 mm) £2.60
Breather Cloth
Consumable Under-bag airflow path and resin catch
0.6 m (1 m wide) £12.00 per 5 m pack (1 m wide) £1.44
Total £13.04

Tools Required

Tool Purpose
Metal roller or rounded tool Press the butyl sealing tape firmly to the base
DIY Vacuum gauge Estimate when vacuum reaches 80% atmospheric pressure
Scissors Cut materials like fabric, film, or templates to size
Window cleaner Degrease surfaces before bonding or sealing

See this page for how to make a DIY Vacuum Gauge: Trapped Balloon Vacuum Gauge

Instructions (step-by-step)

  1. Clean the laminating base edges thoroughly using a cloth and window cleaner to ensure the butyl tape adheres properly.
  2. Cut a sheet of vacuum bag film with sufficient margin to cover the part completely on all sides.
  3. Apply a continuous strip of butyl sealing tape along the edges of the laminating base.
  4. Lay the vacuum bag film over the base, pressing it firmly into the butyl tape to create an airtight seal.
  5. Ensure the vacuum valve is positioned away from critical laminate parts such as the free blade.
  6. Arrange breather cloth around the part to support airflow under the bag, and place an extra layer beneath the valve.
  7. Pump manually while monitoring the gauge, stopping once ~80% atmospheric pressure (-0.2 bar) is achieved.
  8. Check for leaks by verifying the gauge holds steady for at least 10 minutes. If vacuum drops, inspect and reseal the edges as needed.

Limitations

  • Requires a clean and smooth base surface for proper sealing; dust, grease, or moisture will cause leaks
  • More setup time compared to enclosed bagging