Screw hold repair in fabric?

"Brian Huffaker" wrote in message
...

It's annual time on the starduster, and several of the screw holds
to hold on the inspection plates have been enlarged over the years to
the point where a screw won't stay in the whole. Around each inspection
hole, there is a thickened area in the fabric that has been drilled
or punched to recieve the screws. We are using sheet metal screws.
I don't know what covering system was used, but could probably find
out (it was recovered several years before I bought into the
partnetship). Is there some kind of filler that could be placed in
these holes and then drilled out back to a smaller size so that the
screws would stay in?

Thanks in advance for any ideas.

Brian Huffaker, DSWL )
RV-8A 80091 Riviting foward lower fuseage skin
1/4 Starduster Too N23UT flying.

The round inspection hole reinforcements I have seen are made of plastic and
they do get old and brittle and screw holes get elongated. They are
usually thin plastic rings that have been sandwiched between the wing's
fabric and a pinked-edge patch. Inspection covers best for these are round
aluminum plates which have attached clips 180 deg. apart which you push over
the reinforced hole and then line up the inspection plate so that it is
centered over the hole. The clips holding the cover to the fabric are
hidden inside the wing. On the faster fabric-covered airplanes like a
Pitts or Starduster the inspection cover has an inner concavity which
centers the cover and keeps it from slipping off or off-center. I have
seen some builders drill through the clips and use screws to make them hold
more tightly.

Where I have inspection plates attached to the fabric with screws, I bond a
narrow strip or plate of 016 or 020 aluminum inside the perimeter of the
hole and then use a fabric patch doubler and fold and glue it on securely
with Poly-Tak so that the aluminum reinforcement is encapsulated in fabric.
Then I drill through for the inspection cover screws and VOILA!, the
inspection cover hides the patching and the fabric doubler and lasts
forever.