11. Spreading epoxy. Care must be taken not to remove too much epoxy and leave it dry. Too little epoxy and there will be cavities where the cloth overlaps. This will then require filling after the wing is finished.
12. Spreading epoxy. The piece of Spectra that becomes the elevator hinge is fully penetrated by the resin. Later, the carbon skin will be cut around the elevator, with a 1mm wide strip removed at the hinge line to allow the Spectra to flex.
13. The carbon is wet out and the excess runs to raised areas. Later, the bottom wing half will be moulded in this same mould, with the elevator consisting of just 2 layers of carbon fibre cloth, positioned on the opposite (outboard) side of the wing. It too will later have the carbon fibre skin cut through the elevator outline to allow the elevator to move.
14. A piece of cotton bed-sheet cloth is cut and applied over the top of the first plastic sheet (vacuumn bag). Then another plastic sheet is sealed completely over the first.
15. The second bag has the air removed and applies even pressure over the carbon and epoxy.
16. The epoxy I use is LC3600, which I cure at 40 degrees C. The Carbon and epoxy is pushed down again after 1 hour and then again after 2 hours.
17. The mould is heated from below with a water bed heater to 40 degrees. The heater is hidden in this picture. Insulation is put over the top and allowed to cure for 12hrs
Enlarged view
18. After 12 hours the bags are removed. The water bed heater that was hidden in picture 17 can be seen here as the pink thing emerging from under the mould. It's a solid state heater. Power and temperature sensor wires can be seen in picture 10, running under the right hand end of the mould.
19. The carbon and epoxy is sanded with 240 grit to roughen the surface.
20. 3 grams of epoxy is applied and spread using a card first. then a brush. 1 gram goes to the brush.
