Posted for bob mackey <n103md@yahoo.com>:

 Do as Jim Nordin suggested...

  I will repeat his method with a few different details that may be
instructive
  depending on your experience with composite repairs. One of the good
  things about composites, is that there is nothing that can't be repaired
with
  an air grinder and some more material...

  Cut out an oval-shaped hole completely removing the damaged material.
  make the hole big enough so you can do a good job of cleaning out the
  fuel cell. Sand the inside surface around the hole to provide a fresh
bonding
  area.

  You'll need some cloth similar to the original construction, structural
adhesive
  (hysol), laminating resin, core material like the original (foam or
honeycomb),
  microballoons, and so on. I would choose a laminating resin that will retain
  some flexibility when cured. One of my favorites is Applied Poleramic's DR-5
  with the EH-102 hardener (Thanks to Dan Newland for that suggestion). It is
a   two-phase toughened resin that will not crack and start leaking due to
flexing.

  If the repair area is fairly flat, you may be able to use a 2-3 bid sheet
laid up
  on a flat surface. As Jim suggested, cut this after curing to make an oval
patch
  that can go in through the hole and then overlap 3/4" or so all the way
around.
  Mark it so that you can see when it is correctly alligned.  Attach a handle
that
  can be used to pull the plug tight in the hole, and then removed later. Tie
a   string to the handle and place the part inside the wing.

  If the repair section is not so flat, then you'll have to form the patch to
the
  right shape somehow.  A nearby section of the wing can be used as a mold
  by simply pulling some plastic over the surface. I sometimes make a foam
  mold by sticking sandpaper to the outside of the wing and grinding the foam
  to fit the wing contour. then build the part inside that mold. After curing,
  trim to the right size and attach a handle as above.

  Build up a ridge of Hysol around the hole on the inside of the wing,
  and pull the inside patch into place. You should get good squeezout
  all the way around the patch. But not so much that loose peices of
  Hysol will be getting loose in the fuel bay.

  Sometimes, a little pressure can be applied to the patch by connecting a
  balloon to the fuel line and plugging the vent (or vice versa). The key is
to use
  only enough pressure to hold the plug in place, and not so much that the
  patch is distorted or the wing damages. Scrape out excess hysol before it
cures.
  After it cures, remove the handle.

  Scarf (taper) the outer skin from paper thin at the edge of the hole to full
thickness
  about an inch away. The disc sander does this quickly and easily.

  The next several steps can be done all at once if you use a slow resin and
  good skills. If you're not sure, do it one step at a time and let things
cure in
  between.

  Cut a piece of core to fit the hole, and bond it in. If using honeycomb,
lightly wet
  the inside of the hole with laminating resin, and wet out a film on your
work bench,
  then slide the honecomb around so that just the edges of the honeycomb are
  dampened. Put it in the hole and hold it down with a plastic bag partly full
of sand.

  Fill any gaps between the old and new cores with a stiff mixture of
microballons
  in laminating resin. the texture should be about like peanut butter. If you
let this
  cure between steps, build it up a little proud, then grind it back down to
smoothly
  blend with the scarfed outer skin.

  Wet the top surface of the core with a foam roller.
  Lay up the appropriate number of wet out BID in place after squeegeeing or
rolling out
  any excess resin between two layers of plastic film. Remove one of the
plastif films,
  and lay this patch over the hole, extending just past the scarfed area all
the way around.
  Use a sandbag (or vacuum bag if you have the tools and know what you're
doing)
  to hold the new skin in place as it cures.

  Finally, sand with long boards and sharp abrasive paper to match the
original contour.
  The old paint will act as a guide coat.

  Bodywork and repaint.

  Then whatever it was the broke the wing in the first place, don't do it
again.

  -bob mackey