Merry Christmas to all!

It seems like a decade ago when I installed my rudder cables before closing the vertical stab, both pilot and co-pilot. Prior to final installation, the cables were cleaned multiple times with MC. A trial fit in the nylon tubes revealed what appeared to be very minor friction.

My elegant solution(which you should all avoid like the plague), was to obtain a sample of teflon powder from Dupont. The Dupont chemist suggested that I mix up a slurry of teflon powder and isopropl alcohol, impregnate the cables with this solution and allow the alcohol to evaporate. When dry, the cables were uniformly coated with teflon. So far, so good. After installation, all friction had vanished. It was almost as if 1 gram of pressure applied to a cable end would send it slithering on its way in its tube.

Fast forward 9 months...the time had come to attach each cable to the firewall. Disaster had struck, the cables would not budge in their nylon tubes. With great effort, I was able to reach in behind the baggage bulkhead and pull each cable out of its tube to the rear. What I found was disheartening. The super slippery teflon powder on the cables had transformed into a thick sludge, not unlike high viscosity motor oil at low temps. In addition, it was apparent that a lot of crud was left behind in each tube.

It turns out that lubrication of some sort is used in the cable manufacture process and all the cleaning prior to applying the teflon slurry only effected the exposed cable surface. Over time, the lubrication left on the interior of the cable strands leached to the surface and combined with the teflon to form the thick sludge.

All is squeaky clean now, the cables have been lightly coated with Mobil 0W40 synthetic oil and returned to their tubes.

Angier Ames
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