The S247 Carbon Fibre Hardtop primary purpose is to protect the crew of the Sunseeker Hawk 38 from sea spray and head-wind due to this performance day boat’s high-speed capability. The hardtop also acts as a roof to shield the occupants from sun and rain depending on weather conditions.
As this hardtop is the highest point on the boat, it’s has been manufactured to be as light as possible that keeps the COG lower down in the boat. The carbon fibre finish is visually appealing and adds to the premium feel.
We have manufactured carbon fibre tooling from the customer supplied patterns, while the tooling is capable of curing the part at a maximum temperature of 120˚C. This ensures there are no concerns with thermal expansion compared with a typical glass fibre tool.
The carbon fibre hardtop is manufactured from prepreg and foam core to form a rigid sandwich structure.
All of the plies are CNC cut on our CNC ply cutter and are positioned into the mould using a lay-up book instructions. The CNC ply cutter is a massive benefit to the process particularly for the lower surface of the hardtop that is a lacquered carbon finish with a herringbone joint through the middle of the part. Keeping this joint straight between 4 individual cut pieces would be a challenge without utilising the CNC machine.
Once all of the plies are laminated the part is cured in the oven at 90˚C under vacuum pressure.
The upper skin of the hardtop is removed from the tooling and trimmed to the EOP lines. The return joggle flange of the lower skin is removed to allow the flange to be trimmed. The lower skin of the hardtop is not removed from the tool to ensure the profile is not distorted during the bonding process.
The internals of the hardtop (metallic plates & ribs) are then bonded in using cold curing adhesives.
The upper skin is lowered onto the lower half as a dry fit to ensure the edge closes up to the lower mould tool all the way round. If acceptable the upper skin is removed, all bonding surfaces are prepped and cleaned and the adhesive is applied, the upper skin is repositioned and then clamped as required.
After the adhesive is cured and post cured the bonded hardtop is removed from the lower tool. The part is trimmed to its final condition and inspected prior to the paint process. The hardtop is a split finish with a carbon lacquered finish on the lower skin and painted solid black on the upper surface.
Manufacturing the S247 Carbon Fibre Hardtop for Sunseeker expands NORCO’S current portfolio of work with this long-established customer outside of normal product requirements.