"Honeycomb is certainly a structural core material; all the AC boats have it as their hull and deck core."

I was not saying that "honeycomb" or “Nomex” was not a structural material...what I was pointing out was that the "type" of Nomex that Spruce Aircraft was advertising specifically stated it was for non structural purposes. Due more research ncik and you will find umpteen different varieties of honeycomb reinforcement out of all types of material....and several varieties of Nomex as well. PN1 Commercial grade Aramid Fiber Honeycomb is used in boat hulls. PK2 Kevlar N636 Para-Aramid Fiber Honeycomb used for boat decks. PN2 Aerospace Grade Aramid Fiber Honeycomb used for aircraft wings, missile wings, helicopter rotor blades etc.

Regards,
Bob