On Mon, 08 Mar 2010 09:35:23 -0800, Darryl Ramm wrote:

On Mar 8, 9:05Â*am, Martin Gregorie
wrote:
On Mon, 08 Mar 2010 06:05:32 -0800, JJ Sinclair wrote:
Martin,
All Libelles use only epoxy resin. In the early days some were
concerned about their ship getting too hot sitting in the trailer,
hence the note in your flight manual. I take it you have a H-301, if
so the opaque looking areas on your wings are probably thin gelcoat
allowing the balsa-wood core to show through. keep moisture away from
her and she's a good old girl............ I have owned 2 and loved
them both, but that removable canopy became too much for an old guy
to tolerate.

Thanks for clearing that up, JJ.

I have an early H.201, s/n 82, so its definitely got balsa-skinned
flying surfaces. As a somewhat ex aeromodeler I can still recognise
balsa and know what it looks like under an epoxy/glass finish having
finished bits of several models that way.

The tan layer under my Libelle's wing and tail gelcoat is definitely
not balsa - its an even, textureless mid-tan colour with a matt finish.
There's a square inch or so exposed round the tailplane's front
hold-down where the tape I put over the hold-down has lifted some of
the gelcoat off. IOW there's sufficient of it exposed to be confident
of its lack of texture. Besides its a considerably darker yellow-brown
colour than I've ever seen on a piece of balsa. I'm now really puzzled
as what it might be.

Is this only in spots like the wing root and near the tail attach bolt?
Could it be phenolic microballoon filler?. You'll get that in different
brown to reddish-brown colors, maybe tan. I think phenolic microballons
have been around for ages, but I have _no idea_ if it was ever used in a
Libelle.

I'm pretty sure I've I've seen it under a chip further out on the wing,
made when a 'helper' slung the tail dolly into my trailer, bouncing it
off the wing undersurface.


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martin@ | Martin Gregorie
gregorie. | Essex, UK
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