Unlike the top surface of the wing where the spar is level all the way to the wingtip, it tapers up to the wingtip from the last full size rib. This creates a natural angle to make a scarf joint between the main wing skin and that of the tip so the tip can be skinned first and then sanded level with the line of the main ribs to create the scarf joint with the main lower wing skin. Crucial to this working is the fact that the bottom of the last full size rib was sanded to match the slope of the wingtip rather than just being flat like the other ribs.A piece of the 3/32" mahogany ply was cut out to roughly match the shape of the wing tip. This was then clipped to the wing and the position of the ribs and spars marked on the inside of the skin in pencil. Sacrificial strips were cut from scrap ply to enable staples to be used to secure the skin while the glue set which could then be removed without damaging the skin proper. The rib and spar positions marked on the inside of the skin were also transfered to the outside to allow positioning of the staples.
Then a batch of West Systems epoxy was made with the usual 5% by weight of microfibre. This was applied to the wing tip structure and between the pencil marks on the inside of the skin. The skin was then positioned onto the wing structure and fastened into position with staples from the spar outwards. Every clamp I possess was then used to secure the edges of the skin and the glue left to dry overnight.
