On Tuesday, December 15, 2020 at 5:28:12 PM UTC-5, John Sinclair wrote:
On Tuesday, December 15, 2020 at 1:37:53 PM UTC-8, Hartley Falbaum wrote:
I just wanted to alert you to a problem we found with our K21.

We have used Tesa cloth tape for aileron and elevator seals for over 20 years with no problem.

Last winter I used cloth tape from Berry Plastics “Polyken”. The roll was from a trusted tried and true USA glider supply source, and fairly new
though I don’t recall exactly how old is was then. No more than 1 year though.

All was well all year, until a month ago when the ailerons progressively got much stiffer in the last half of travel either right or left. It got cold in Georgia.

After much sleuthing, consulting with trusted advisers well known to us, and head scratching, we got the key clue from Rex Mayes. We removed the tape seals and normalcy was instantly restored. The tape had shrunk.
The tape was really stuck! It was very stiff after removal.

In short, I would not recommend any cloth tape but Tesa for these seals..
I have notified the tape source of the findings.

Hope this may save someone else a lot of effort one day.

Hartley "KF" Falbaum
MGSA, Georgia USA
That’s a fairly common problem, Hartley.
After locking the control in the fully deflected position, I start the tape and then lay a pencil in the groove so as to make the tape sink in a pit, then press down on both edges of the tape..............I remember the guy that taped all his controls in neutral, then called me complaining he couldn’t move any of the controls!
JJ
Indeed yes JJ. These seals operated properly all year. We've been taping the controls for over 20 years with no problem. This tape is different. That is my point.