I would like to beat this dead horse a little more.

I will check and rephrase my "cross-linking" term. I would like B. =
Lacovara to explain the additional protection afforded at the surface of =
a very shiny, smooth de-molded gel-coat part that is not aggressively =
sanded/polished. I do know that in many cases this cracking/crazing =
follows the exact pattern of the sanding strokes/motions that are =
performed at the factories. Note the cord-wise cracking on LS products. =
They used to do much of the sanding in that direction. They also used =
jitter bug type sanders on the back bones of the fuselages. You can =
observe these "eyelash" shaped cracks all down the surface of the spines =
of many LS gliders. Schleicher's wing control surfaces crack =
span-wise...the direction of sanding. Final grit numbers and direction =
of sanding and follow-up polishing can make a huge difference in surface =
longevity too. This was explained to me an a very large repair facility =
in Germany a number of years ago when they demonstrated span-wise final =
sanding in two stages, followed by a chord-wise direction of the polish =
machine. DG employs this technique. Lacovara's paper confirms that =
surface "roughness" allows faster degradation on several levels. You =
can increase the life of your factory gel-coat finish by sanding the =
surface with 1500-2000 grit paper and polishing ACROSS this sanded =
pattern, increasing the gloss. There are a number of polishes suitable =
for this, including the hard stick polishes used by the factories and =
3M's Finesse it and Perfect it systems, just to name a couple. Follow =
this up with WX seal/block system, and you are well on your way to a =
happier gel-coat surface. =20

Dry out your ship, slick it up, use WX block system once, preferably =
twice a year, NEVER tie it out, and store it in your trailer inside a =
basement or hanger, etc..

P. Gaines=20