Building adventures of an Ultralight Glider: Wing covering, Part 3

Saturday, August 31, 2019

Wing covering, Part 3

The final item on the wing covering to-do list was the aileron linkage cutouts. Similar to the elevator linkage area, I added a piece of thin sheet metal with a slot in it to stiffen the cutout. Lesson learned with the elevator area though, the covering has a LOT of tension and can distort that piece of thin material. So I bent a lip most of the way around the cutout to stiffen the part from bending like a potato chip.

From previous marks (before adding the top covering) of the centerline and ends of the travel, I knew where to place the reinforcement. The pencil marks show the outline of the metal reinforcement.

Next is a coating of adhesive on both the fabric and the back of the metal reinforcement. I never quite figured out the best amount of time to wait before sticking these two together -- the Stewart Systems videos on Youtube say to do this wet, but it is easier if it is dry. At any rate, I stuck it on and then used an iron to encourage the adhesion.

I then drew another pencil outline and put a healthy coat of wet adhesive inside the lines, including over top of the metal part. The cloth patch now goes on, pushing it with the brush into the wet glue. It is visible in person to see when it is completely wet out and without wrinkles. Another coat of wet glue is spread on top and wiped off when it is still "aggressively wet."

After drying overnight, I went back over the edges with an iron set to 250F to smooth down the mini frayed edges as the pinked cut, and to stick down any little bubbles. I also shrunk the whole wing to 275F so the covering was all set and putting tension into the patch. With a committed sigh, I cut the inside covering slit and was relieved the metal reinforcement did not distort when taking the tension! A little clean-up around the covering edges, some more coaxing of the bend with the pliers, and a final trim of the covering to the edge, and this task is done.