This is a copy of an article on GAP SEALS that appeared on the LML on 10/10/2003.  It was titled " 6 knots for $104" and was written by Carl Cadwell.  My copy didnt age too well  but I'll do my best to be accurate.

"First, my thanks to Doug McAlister who first did this and put me on to the idea.

I installed gap seals on all the control surfaces (top and bottom of ailerons and elevators;  both sides of the rudder), and trim tabs (on the non-hinged side) for for the rudder and elevator .  I gained 6 Kts IAS at FL 240 and 250.  This is where I fly most of the time and know my numbers, power settings, etc.  The lowest number I see is 6 Kts IAS increase to 8 or 9 Kts.  So I am claiming 6 Kts.  I have taken 6 flights now with the same results.

Doug tufted his ailerons and observed flow that used to separate ahead of the ailerons now separates part way down the ailerons.

The handling seems to be the same with perhaps (maybe) a little more roll response at slow speed.

Source:
Eastern Sailplane
398 Miami St.
Waynesville, OH 45068
513.897.5667
fax:513.897.5909
www.easternsailplane.com
John Murr:

TAPE 00051  MYLAR PROFILBAND 30mm  15 m for elevators and ailerons
TAPE 00050  MYLAR PROFILBAND  38 mm  15m for rudder
TAPE 00090  TESA  SAFETY TAPE FILM  25mm or 30 mm

The mylar can be ordered in the roll or by the foot.

Layout 1/2 wide section on the trailing edge and sand lightly with 400 grit.  Clean.
Apply mylar.  Apply safety tape lapping 1/2 " onto the mylar.
Do not sand on area under safety tape

To maybe prevent icing from building up on the rudder counterweight and preventing elevator control, I also put 2 small pieces on my horizontal stabalizer that covers the leading edge of the counterweight.
Thankfully, I have not accumulated any ice to test if this works or not.  A future report if this happens to help

Carl Cadwell
N25CL 450 hours L-IVP"

P.S.  My thanks to Carl C. for his information  Bill Hogarty