WATT AGE PT-19 CORNELL EP ARF Instructions For Final Assembly - page 9
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❑ Carefully slide both wing panels together with the wing joiner
temporarily installed (without using glue).
❑ While holding the two wing panels together firmly, make sure that
both wing panels are lined up at both the leading and trailing edges,
then look carefully at the center-section joint: the wing panels should fit
together tightly with few or no gaps in the joint.
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✦IMPORTANT✦
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✦ If the wing panels do not fit together properly, remove the wing joiner and use 220 grit sandpaper with a
sanding block to lightly sand the tips of the wing joiner, until you are satisfied with the fit. Remember, when the wing panels are
pushed together, there should be few or no gaps in the center-section joint.
❑ When satisfied with the fit and alignment, pull the wing panels apart
and remove the wing joiner.
❑ Apply a strip of masking tape to the top and bottom edges of the root
rib on each wing panel.
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The masking tape will prevent excess epoxy from getting onto the
wing panels when you join them.
STEP 2: JOINING THE WING PANELS
❑ Mix a generous amount of 5 minute epoxy. Working with only one wing panel for now, apply a thin layer of epoxy inside the wing
joiner box and to only half of the wing joiner. Make sure to cover the top and bottom, as well as the sides, and use enough epoxy to
fill any gaps.
❑ Slide the wing joiner into the wing panel up to the centerline you drew. Quickly remove any excess epoxy, using a paper towel
and rubbing alcohol, and allow the epoxy to set up before proceeding.
❑ After the epoxy has set up, test-fit both wing panels together again to double-check that they still fit together properly. Check the
leading and trailing edges, too. It's important that they be even with each other.
❑ Mix a generous amount of 5 minute epoxy and apply a thin layer to the exposed half of the wing joiner, the inside of the wing
joiner box in the second wing panel, and the entire surface of BOTH root ribs. Make sure to use enough epoxy to fill any gaps.
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✦ It is of the utmost importance to the integrity of the wing center-section joint that you apply a generous amount
of epoxy to both root ribs and the wing joiner. Not using enough epoxy can result in wing failure during flight.
❑ Slide the two wing panels together and realign them. Quickly wipe away any excess epoxy, using a paper towel and rubbing
alcohol, and use pieces of masking tape to hold the two wing panels aligned until the epoxy fully cures.
STEP 3: CHECKING THE WING CENTER-SECTION JOINT
❑ Once the epoxy has fully cured, remove the masking tape and double-check the center-section joint. If any gaps are present,
mix a small quantity of 5 minute epoxy and carefully fill any remaining gaps.
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✦ Do not omit this procedure. The wing panels should fit together tightly, but it's possible to have some small gaps
that appear after the epoxy has cured. To make the wing center-section joint as strong as possible, it's important to fill any gaps,
using 5 minute epoxy.