On Tuesday, November 17, 2015 at 12:03:28 PM UTC-7, wrote:
It's great to hear that my old LS-3 is being rejuvenated with such care! A few words of explanation.

AFAIK, that's the original gel coat. I owned it from 1978 through 1992 and I don't believe there has been a refinish job in the interim.

All crazing lines followed an underlying surface defect or discontinuity.. For example in my wings, stab, and fuse they followed previous sanding patterns perfectly.

Not sure about this one. I contoured the wings twice and profiled the top surface once. All sanding was done at 45 degrees. After the first three years they were generally left at 400 grit, unwaxed, so rain would spread rather than bead up. Roberto, were the crazing lines at 45 degrees? The wings had crazed hardly at all when I sold it, and I often wondered if that was because the gel coat was likely much thinner and less brittle than when it was new due to the three cycles of sanding/smoothing. I did sand with much finer grit to remove sanding marks, polish, and wax the wings the year before I sold it.

Neither the fuselage nor the stab was ever sanded post factory, to my knowledge. When new they were a high gloss so I'm wondering what the "previous sanding patterns" were. The only significant crazing evident when I sold it was on the filler at the tips of the stab, IIRC.

When I sold it, I changed the registration # and contest ID for the new owner, converting JB into JE in both cases with some rubbing compound. At that time, I also was startled to find perfect gel coat underneath the paint.

Interestingly enough there was a perfect craze line that matched the exact pattern of the underside original owners initials that where painted on the wing, JB.

IIRC, the contest ID and registration # on the vertical fin were both scribed around with some kind of sharp tool at the factory, I guess to prevent paint from creeping under? I didn't discover the scribe marks until I polished off parts of the JB. They proved impossible to remove without sanding (which I didn't do). I can't recall if the contest ID under the wing was applied using the same technique but I wouldn't be surprised. That could explain the cracks.

When I bought my ASW 24, I'd already heard of one glider that had been sprayed with paint when new to protect the gel coat. But the LS-3 wings had shrunk over the spar caps so significantly in the first few years that we had to build up the surface with gel coat when profiling them. As a result, I didn't consider painting my new ASW 24. Those wings, however, have been marvelously stable, apparently due to different construction techniques. I've been told the ASW 26 and 24 were built differently than subsequent models (e.g., ASW 27) and are quite stable, though more expensive to build.

Chip Bearden
ASW 24 "JB"
U.S.A.

I uploaded the pictures of the sanding. Let me know what you think of the criss-cross patterns. Quite intriguing. If you can, download the full resolution pictures of the wing reflecting the setting sun (The ones with the pocket knife). You can see the crazing troughs in some of the remaining contact material. The link is: https://picasaweb.google.com/1110763...KeDoqXAyfGiqwE

Roberto