I have some expensive experience to pass on , concerning choice of ply in covering.
I repaired and then built , from a 51% kit a Spacek SD1. When it arrived I was shocked at the hollows and ripples in the ply surface of the parts already built. Instead of returning it ( at my cost!) I went ahead ,planning to fill the depressions.
I eventually sold it because no matter what I did the surface looked bad, especially when I put a base coat of white on it. My worst fears were realised, potential buyers thought it had been left in the rain!
, actively helped by the local agent who wanted to shift the blame.My financial loss amounted to over €6500. not counting 400hrs work and a lot of frustration and unpleasantness.
Having seen a Luciole in construction I realised the problem came from the choice of the ply for covering. The Luciole uses Okoume of 1.2 mm -the same weight as the birch ply on the SD1 of 0.8mm . The okoume stays quite flat no matter how long you store it and is very easy to use, appearing to have little built-in tension. The birch ply , even much thicker, buckles in all directions no matter how it is stored and a 0.8mm covering resembles an old wetted paper bag.
In addition the extra thickness of the okoume resists buckling (girder effect). All the test were exhaustively done by the designer of the Luciole, M. Colomban.
I proposed to Mr Spacek (maker of the SD1) doing an extra tailplane to test the difference , he didn't even reply.
I advise other builders to use Okoume despite being a bit more expensive. The appearance matters a LOT in giving a buyer confidence, and we all have to consider selling the plane on one day.
I repaired and then built , from a 51% kit a Spacek SD1. When it arrived I was shocked at the hollows and ripples in the ply surface of the parts already built. Instead of returning it ( at my cost!) I went ahead ,planning to fill the depressions.
I eventually sold it because no matter what I did the surface looked bad, especially when I put a base coat of white on it. My worst fears were realised, potential buyers thought it had been left in the rain!
, actively helped by the local agent who wanted to shift the blame.My financial loss amounted to over €6500. not counting 400hrs work and a lot of frustration and unpleasantness.
Having seen a Luciole in construction I realised the problem came from the choice of the ply for covering. The Luciole uses Okoume of 1.2 mm -the same weight as the birch ply on the SD1 of 0.8mm . The okoume stays quite flat no matter how long you store it and is very easy to use, appearing to have little built-in tension. The birch ply , even much thicker, buckles in all directions no matter how it is stored and a 0.8mm covering resembles an old wetted paper bag.
In addition the extra thickness of the okoume resists buckling (girder effect). All the test were exhaustively done by the designer of the Luciole, M. Colomban.
I proposed to Mr Spacek (maker of the SD1) doing an extra tailplane to test the difference , he didn't even reply.
I advise other builders to use Okoume despite being a bit more expensive. The appearance matters a LOT in giving a buyer confidence, and we all have to consider selling the plane on one day.
