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Yellow Dragonfly Construction Log

Chapter II - The Repair

After several weeks of planning, we were able to get Matt Gunsch to fly out from Phoenix to my house to inspect and repair the canard.

Matt is a Dragonfly Mark III owner and A&P mechanic. Although his first love is wrenching on war birds, he is skillful in repairing canards, having repaired his own. In addition, he successfully completed a static stress test of his canard, loading it to 3.8 g's by piling sand bags on the jigged canard.

Matt arrived on October 30, 1998. The next day he inspected the damage and determined that it was old damage, but probably due to the pilot's heels bouncing on the canard while in flight, compressing the foam core, and allowing the fiberglass buildup to pull loose. The airplane sitting on it's gear in the heat, then caused the fiberglass to begin to buckle.

Here Matt is using the "coin tap" test to define the edges of the delaminated area. He's using a marker to lay it out.	A sample cut was removed from the buckled area. The sample showed that the layers of fiberglass were sill intact, although it separated from the foam.
This photo shows the area that Matt found to be unattached.	Since we'll be converting the Dragonfly to a Mark II, it's time to remove the wheel pants.

1/8" holes were drilled through the layers of buckled fiberglass.
A microballon and epoxy slurry was then injected into the void,
through these holes, until micro oozed out from the adjacent holes.
A very large syringe with out a needle was used. It was purchased
from a local veterinary supply house.

Not the most professional looking, we
were able to find enough stuff to pile on
the repaired area to weigh it down.

After almost a week of curing, the weight
was removed, and the repaired area was
sanded so I could add more glass.

This is when I noticed what I consider to be the real cause of the buckling. This canard had the plans built rudder system installed at one time. Someone removed the glassed in place phenolic blocks from on top of the canard, and in doing so, removed quite a bit of the unidirectional cloth which makes up the last layer of the glassing schedule.

In addition to replacing the glass from the areas where Matt took the samples,
I laid 2 layers of unidirectional glass cloth over the entire center section.

Here are the 2 layers of uni just after
I glassed them in to place.

Since it gets cold here in October, I set
up lights to keep the glass warm.

The following day, I used a bit of solar heat to help the process.
Even though the lights did a fine job, I really wanted this layup to cure right.

The surface temperature never got more than 90 degrees, either in the sun
or under the lights

Esse site foi ideia de Patrick Panzera de Hanford California EUA.

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