[aus-soaring] Scheufler T35 gelcoat

[Roger Druce]

Re Scheufler T35 gelcoat, my experience with my 1993 Schempp-Hirth Janus CT finished in T35 gelcoat is as follows.   In 1999 at 6 years age and 300 hours time in service, a few very faint, but classic gelcoat failure, cracks appeared on the post moulding gelcoated centreline of the fuselage nose upper.  Searching elsewhere with a 15 times quality monocular viewer revealed no other problems elsewhere at that time.   Not being prepared to go through gelcoat failure yet again I had the wings overpainted by Joe Luciani mid 2000 after he and I confirmed no gelcoat failure cracking with the wings.  Later in 2000 inspection of the fuselage showed the faint onset of cracking on the fuselage centreline upper aft of the wings again in post moulding gelcoat work.  And the 15x viewer also found faint problems on the starboard fin upper surface which was an area gelcoated within the mould.  (The fin problem may perhaps reflect long winter storage in the workshop right next to the window?).   So 2001 has seen the fuselage overpainted by Joe after dealing with the affected gelcoat areas albeit that indications were faint.   My impression is that the fuselage finish is not final finish sanded to the same degree as the wings.  Under 15x viewing the fuselage sanding looks rougher compared to the wings.  The faint cracks on the fuselage follow sanding marks.   So my experience is that Scheuffler T35 as applied by Schempp-Hirth at that time is not a durable finish.  Thanks Joe Luciani for a great paint job and helping me deal with the problem at its faint start & well before it would have gotten way out of hand.   Owners with T35 gelcoat on their gliders should be vigilant and not complacently believe that they will have no problem.  Look at your gliders gelcoat with a quality magnifying viewer regularly.   Roger Druce