On Nov 18, 10:10*am, Mark Jardini wrote:
aren't most of last decade birds built with epoxy resin?

Yes, but what the glider is made of does not dictate what the fuel
tanks is made of. And a fuel tank might well have a special fuel-proof
lining even if the tank is made of other resin. Check with the
manufacturer, and check if they believe the aircraft should use
alcohol blend fuels. And many motorgliders also have aux fuel stored
in the wings - in flexible bags not hard tanks.

Darryl