Although building fiberglass parts via vacuum infusion isn’t a new process, it is typically reserved for high-end and high-performance products such as aircraft, supercars, and race boats. Once the basic concepts are understood, the process can be repeated consistently to produce high-quality laminates not possibly via hand lay-up techniques.
Key Equipment:
- Vacuum Pump – The star of the show! The pump provides the pressure differential necessary to draw the resin through the dry laminates and optimally wet-out the materials.
- Vacuum Bag – The bag completely encloses the part and applies constant, consistent vacuum equally across the part.
- Resin Traps – Pressure pots are used between the vacuum bag and the vacuum pump to test the initial vacuum of the bag, and to protect the pump from ingesting excess resin from the part.
- Sealant Tape – Used to seal the bag to the outer edge of the mold and provide an airtight bond between the mold bag and the vacuum bag. Additionally, the tape is used to repair leaks in the bag.
- Vacuum and Feed Lines – Semi-rigid tubing connecting the various vacuum components (the pump, the pressure pots, and the vacuum bag) to one-another. Spiral wrap tubing is also used to direct the vacuum or feed lines as necessary.
- Spray Glue – Used to secure the dry laminates to the mold or to previous laid layers of materials.
The Setup:
- Install the dry laminates and coring, using the spray glue as necessary to hold in place.
- Install the vacuum and feed lines per the manifold setup using a flow modeling tool such as RTM-Worx.
- Apply sealant tape to the mold flange and carefully install the bag over the part and secure completely to the sealant tape.
- Connect the resin traps to the vacuum pump.
- Connect the resin traps to the vacuum lines of the bag.
- Turn on the vacuum pump and apply full vacuum of 29.7HG to the part.
- Shutoff the resin traps and perform a drop test to ensure that there are no leaks.
- Once the part passes the drop test for leaks, clamp lines completely shut.
- Connect feed lines and route to the resin source, clamp lines completely shut.
- Catalyze necessary resin and place in resin source.
- Unclamp the vacuum lines and feed lines as necessary to completely wet out the part.
- Once the part is completely wet-out clamp all feeder lines except one.
- Continue to apply vacuum to all lines until the part has reached peak exotherm and returned to ambient temperature.
- Remove bag, lines, and peel ply and dispose.
This process once learned is easily repeatable, the quality of the laminated parts is ensured and far superior to any hand built parts due to the high glass to resin ratio. Additionally, the parts weigh less because only the required amount of resin is actually in the part.
We will detail the results of our first resin infused hull in the next update, stay tuned…
