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Re: REFLECTOR: Thermion

Title: Thermion
Gordon- I have my doubts about the effectiveness of this material inside a fuel tank. I investigated a similar material called ROHMoglas which was aluminized fiberglass mat. Sport Av or Kitplanes had suggested it as a static wick for fuel tanks. When I talked to the company they said it was used for antenna dishes and to make antenna ground planes in fiberglass structures.The rep I talked to thought it would be ineffective as a tank liner.
  Epoxy resin is nonconductive. If you saturate the mat when you bond it to the tank it will be insulated from the static charge. You could wet the tank surface and stick the mat to it leaving the outer surface clean instead. This poses the risk of having fibers break loose, possibly clogging the fuel system. Since the Thermion mat is carbon-fiber it might be possible to seal the tank surfaces with resin, apply the saturated mat, then lightly sand it to break through the epoxy to expose the conductive fibers.
  This may not do much to solve the problem though. I was a volunteer fireman for many years and a chief for a few. I don't claim to have the final word but we were taught that the vapors inside a partly-full fuel tank are too rich to support combustion. It seems to me that the area of greatest danger is the interface where the vapors expelled by fueling mix with sufficient oxygen to become explosive. That would be outside the filler neck. There may be static charges on the outside of the wing as well. 
   Other Velocity builders have pointed out that metal will accumulate the static charges like a condensor. That suggests that the cap and filler neck would be the most likely source for a spark. For my own plane I made a tube of aluminum bug screen which extends from the filler opening to the bottom. The screen should collect static from within the tank and help to keep crud confined to the filler area. It is electrically bonded to the filler neck. The cap is bonded to the neck by a strap which also keeps the cap from getting lost in flight. Fueling procedure will be to ground the cap before opening and keep it connected until fueling is completed.
prototype 'Super' Chipmunk N18EF
Velocity Classic RG N6098S in the works