FAIRCHILD CF-AUJ CRASHED AT LOST BAY ON CONFEDERATION LAKE, ONTARIO
When history’s significant aircraft are retrieved from their crash sites in the arctic, from the bottoms of lakes or the sides of mountains, they’re often in quite rough shape. They’ve definitely had a tough journey and the runways were never paved.
Once the wrecks reach the Museum, a team of voluteers aims to restore the aircaft to its pre-crash state, as authentically as possible. And that means restoring or re-creating the canvas wing structures that were used in the pioneer days of flying.
A technique known as ‘rib-stitching’ has been employed to fasten fabric since the beginning of flight – from the Wright Brothers at the start of the 20th century through the machines of the Great Wars 1914 and 1939. It’s the mechanism used to fasten fabric to the ribs of aircraft. Early pilots needed to know how to do it for quick repairs in the bush, but it’s a lost art, used today only by restoration teams such as the team of volunteers at the Western Canada Aviation Museum.
The team starts with aviation-quality cotton (a very fine weave cotton) to create a smooth airfoil. One continuous thread is applied from leading edge to trailing edge. The stitch itself is begun through the fabric at the top of the wing to the fabric at the bottom of the wing on the inboard side and back up the opposite side of the rib. Then it is tied off with a ‘seine’ or ‘fisherman’s knot’ – a fairly flat knot that is virtually impossible to untie. The procedure is repeated every two or three inches until the entire rib is stitched.
After stitching, the fabric is wetted down with water to shrink it. Once dry, the first coat of dope is applied. Dope is a clear nitrate-based liquid that causes the fabric to shrink even further. It is left to dry and when ready, the tape to cover the stitching is applied and glued to the rib, followed by 5-7 coats of silver-colored, lacquer-based dope. (The silver blocks out the sun’s ultraviolet rays that could break down the fabric and glue.) Then the final paint colour is applied – about two to three coats.
This procedure follows original manufacturing techniques to make aircraft restorations as authentic as possible.
SEW FAR, SO GOOD
A tribute to the craftsmanship of our volunteers has been established at the museum. Drop by any time during regular Museum hours to see the tools, canvas, thread, tape, doping liquid and brushes that made bush repairs possible after a minor ‘dust-up’ with a tree. Or during the war when pesky artillery holes needed repair.
Here’s a link to a video from the Kanvas Aviation Museum, showing how the rib stitching technique works.