Lower sides of Myrsky's wing tips covered
Sunnuntai 11.11.2018 - Member of Tuesday Club
The VL Myrsky II (MY-14) is being restored by the Tuesday Club and its wings are nearly ready in the area between the wing spars. The upper sides of the wings have been covered between the spars, but the lower sides are still without plywood covering. The covering won’t be finished before all the equipment, tubes and wires have been installed inside the wing. However, the covering of the lower side of the wing tip could be partly installed. Here the wing tip part means the rounded end of the wing.
The upper side of the wing tip was covered with a single sheet of plywood, stretching over the whole wing tip area. This was possible because the upper surface of the wing tip is arched only in one direction. The lower side of the wing tip arches significantly upwards towards the tip and also sideways. This is the reason why the lower surface of the wing tip can’t be covered using one sheet of plywood: a large sheet can’t be bent properly into two directions.
The solution was to use narrow strips of plywood which are glued together. These strips of plywood can be bent to match the double arching form of the wing tip.
15 cm wide strips of 1,5 mm plywood were cut to match the length of the wing tip. The strips are be glued together using lap joints, so the edges of the strips were beveled (2 cm of the edge), using a mitre grinding machine. Before gluing, the inner surfaces of the strips were protected using polyurethane varnish, tinted red.
The plywood strips were glued into place one by one, starting in the middle of the wing tip. Heavy weights were placed on the strips after gluing. The plywood strips were clamped tightly on the rib and batten structures of the wing.
The whole lower side of the wing could not yet be covered because the navigation light wiring, etc. has to be installed inside the wing. The covering of the lower side of the wings has been started: three strips of plywood have been glued into place on both wings.