The use of Ammonia & Water would work on an all wood fuselage, but he used a foam "core" for the fuselage, with Basswood sides bonded to the foam.

On an all-wood fuselage, Steam could also be used, but I am concerned about how the foam might react to the heat.

I'm wondering if the warping was either caused by a reaction between the foam and the adhesive used or if the fuselage was un-clamped too soon, before it had fully dried / cured .

Dave F.