Vacuum Resin Infusion
At the heart of our technology is the process we use. All of our parts are vacuum resin infused. The vacuum resin infusion process;
- Removes of ALL air between the fibers of the part prior to the introduction of resin.
- Removes are moisture that may have attached to the fibers during storage or layup.
- Compresses the layers of fiber with even pressure into the exact shape required.
- Maximized the fiber to resin ratio to ensure maximum strength to weight ratio.
The special low viscosity resin is pushed into the part with atmospheric pressure. The part is then left cure at an elevated temperature to ensure the amount cross linking of polymers is maximized. The part is slowly cooled and removed from the mold.
The parts are then post processed. The edges are normally sanded smooth and the face surface is lightly sanded to allow for good paint adhesion application
Core materials are introduced into the part in increase the moment of inertia of a part. When a part is subject to bending with a load from the top, the top of the part is in compression and the bottom of the part is in Tension. The further away we move these differential loads the stronger the part. This is the same with I Beam sections of steel or I Wood for floor joist. The core is a structural grade foam. One big difference with Open Waters advance manufacturing techniques is that we buy plain foam. If the part is a complex shape, we cut the foam into section and thermoform is the the required shape. We then glue the foam together ensure a perfect fit. We custom drill the holes for resin transfer to the back side of the mold and depending of material permeability we may add small knife marks to aid in the flow of resin. This process saves considerable weight as purchase scored or drilled cores take on significantly more weight.
We purchase carbon fiber by the 100+yard roll to ensure economical parts. The fiber is cut of the roll to using templates which indicate the required fiber direction. The common materials we carry are; 6 oz uni directional, 4 oz double bias and 6 oz twill material. Are uni directional and double bias materials are stitched instead of weaved. Stitched fabrics are stronger in the required direction as they don't need to bend over/under other fiber and lay flatter. This leads to slightly thinner lighter weight parts.
The Infusion resin we use is performance post cure epoxy resin from Proset. PRO-SET Infusion Epoxies are super low viscosity systems with a range of hardeners to meet the demands of modern infusion processes. PRO-SET Infusion Epoxies result in lightweight, high-performance composites that will withstand long term cyclic loading in the harshest environments. PRO-SET Infusion Epoxies develop excellent physical properties at room temperature and may be post-cured to further enhance performance. Epoxy resin is mixed by weight on calibrated scales and mixed to ensure no air entrapment.
The quality of the construction is checked and documented every step. All products are stored as per manufactures recommendations and batch numbers for each product used can be trace to each boat. We specifically monitor and humidity through the composite construction process. A vacuum is applied for a minimum of 2 hours prior to infusion and all Epoxy resin is degassed after mixing for 5 minutes prior to infusion which eliminates air entrapment and increased product strength. Post cure heating is conducted is a controlled environment with multiple thermocouples monitoring temperatures through the part.