This week on the Whispa prototype, the upper reinforcing stringers on the hull (the beam shelf), were epoxy laminated onto the hull moulds. These are the final reinforcing longitudinal parts to be added to strengthen the hull form.
Next all longitudinal stringers will be faired in, to match the bevels and twists of the hull moulds ready to skin over in plywood. (Images below: Left – View from the transom. Right – View from the bow.)
This assembly method has proven to be an efficient method for achieving the compound curves within the design which plywood cannot achieve when tortured to its limits. The solid foam panels were further lightened (hollowed out) to reduce weight further (some 2kg of weight saving), and will be glued in a stack, before the outer edges are faired in a similar method to the fairing of the hull once skinned in plywood.
The bow section has been CNC cut from a foam material made of recycled drinks bottles (PET) called ArmaCell. We have also placed an order for a motor housing of experimental design from overseas, this will be adapted and integrated into the hull form in the new year.
Currently, we are experimenting with suitable glues to assemble the profiles which will benefit fairing back to the hull profile without creating spots of hard glue. The bow section will have bolts planted within the laminates for attaching to the plywood hull mould.