Bill and Sue,
My gap seals are self-adhesive curved Mylar strips covered with a thin
"safety" tape overlapping the leading edge and the airfoil upon which the seal
is stuck. They are applied on all sides of control surface
gaps. They were designed for 100 Kt sailplanes. They work.
1. The aileron/flap seals were probably only needed on the bottom
(earthward) surfaces.
2. The glue, both seal and tape, is of variable "stickiness. That is,
if it sticks, it really sticks and removal can lift paint or clear coat. If
it doesn't stick, one must ensure that it is adhering in those places where it
has started to lift before each flight. The lifting forces are exacerbated
by the curve in the Mylar.
3. Some of the seals are covering hinge screw heads where I need to remove
the hinge - bummer.
4. The safety tape must be carefully applied in "windy" locations or it
will weaken and tear - a condition that may lead to separation of the
seal.
You shouldn't have these problems with internal seals. Here are some
considerations for a IV (besides much higher speeds)
1. Almost all of your control surfaces have rounded leading edges and
center hinges. This means internal seals, such as wipers affixed to the
spar or skin aft of the spar could be effective (look at an old
Skymaster). For example, a "C" channel affixed there with a "T"
shaped wiper held by the C.
2. Because the flaps (Fowler) actually separate from the wing skin, a
weather strip type seal might work - sealing when the flaps are completely
retracted and no tape to rattle around off the TE when the flaps are
extended.
3. I don't see any maintenance issues for hidden seals.
Good Luck.
Scott