Instinct F5J: Tailplane Joining

Instinct F5J. After the inside layer cured and was removed from the oven, the shear webs for the main spar were cut from pre laminated 4mm Rohacell 51 IG-F with 25g glass cloth laid at a 45 degree bias on both sides of the web. The reinforcements either side of the elevator hinge line are made from drinking straws and carbon sock, these are perfect as it reduces the weight as they squash to the exact shape. Cutting a shear web is too tricky as there is hardly any depth, the straws make this very easy.
A mix of epoxy resin, cotton flock and micro balloons is piped to the leading and trailing edges and is also used to join the main shear web. Cotton flock is a glass fibre based reinforcement which looks like very tiny pieces of cotton wool, these ensure that the epoxy is bound together and not brittle, this is where the real strength of the join comes from. The micro balloons are microscopic balls of fibre glass almost like glass dust, these are extremely light weight and are used to bulk out the resin mix without any weight penalty, this makes the paste like mix go further and reduce the overall weight of the finished product.
With the moulds carefully trimmed the paste mix is put in a bag, the corner of the bag is cut off and now we apply the mix to the prepared skins like icing a cake. The carbon socks with straws inside are wetted out and placed carefully to the exact measurements, the shear webs are added and then the top mould is married up with the bottom mould and then clamped together. This is placed back in the oven at 30 degrees for 24 hours and then the temperature is increased to 50 degrees for 10 hours which will post cure and harden even further the resin and the finished tailplane. I am away for a few days in Germany with work so I will be de-moulding and sharing the results when I get back on Friday........ :-)