Building the walk through cockpit version of Harrigami.

Reports: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Week 3: Monday 16 - Friday 20 of December 2002

The week was started by fibreglassing both the hulls. The fibreglass was layed out dry (lengthwise) and cut to size. Bote-Cote epoxy was then mixed and poured over the fibreglass and spread with squeegees. Once both the hulls were completed a coating of filled epoxy (q-cells) was spread over the hulls. By adding this layer before the epoxy had completely cured we avoided having to sand the fibreglass. Epoxy can form a waxy residue called amine blush which prevents a good bond with further layers of fibreglass unless removed. This layer of 'bog' (putty in the U.S.) prevents the amine blush from forming, gives a protective coating to the hulls and is the first stepin the fairing process.

Once cured the hulls were lifted from their moulds. The hull shells are very flexible at this stage so leaving a few mould frames in place helps keep their shape. The insides were then ground using a 9" grinder with 40 grit paper and the holes bogged. A set of cradles were made to rest the shells in and the inside surfaces fibreglassed. It is very important to maintain the shape at this point. For the windward hull we only layed a couple of fibreglass drops (running across the hull) after removing a few mould frames. These frames were replaced once the epoxy had dried but not cured. We let this cure over night then fibreglassed the rest the next day, again replacing the frames when dry. This allowed us to always maintain the correct hull shape. For the leeward hull we fibreglassed the inside of the hull longitudinally, replacing the frames when dry but not yet cured. When both hulls were fibreglassed they were hung overhead from the rafters until needed.

Both strongbacks were set up again and another couple of shells strip planked, glassed and bogged ready for removal and inside glassing on Monday. The second windward hull half is only planked up to the bridgedeck level which we had already marked onto the mould frames when tracing from the full size plots.

We also built a narrow bench along one wall for laying up the tops and sides of the beams. Two beam tops were strip planked and glassed with many layers of uni glass. This allowed us to keep busy if we finished epoxying the hulls before the days end.

Hours: 109 (total 208)

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