Dave wrote: "Now, if it was a glider or only had the header tank, yes Blue would be good." You neglecting the fact that every Vari and Long Eze ever built has blue foam wings that are adjacent to the tanks built in the strakes without any catastrophic effects that I know about. If I had it to do over I would use the blue foam (hot wired) for all the flying and control surfaces. I think that would prevent most of the delaminations we see with the urethane foam surfaces.
Rick Human N202RH Houston, Texas