mach082 said some early Gippsland Aeronautics GA8 Airvans have had problems with the sealant coming off the spars and blocking the fuel system.
What a load of dribble, i contacted i guy i know at the factory and he said what you described is completly untrue and that there have never been any problems with sealant coming off spars and into the fuel system causing fuel system blockage. In fact he report that there have been no reported cases of fuel starvation.
Wasn't sealant, was metal shavings from the wing spar blocking fuel filters. Happened to a Kimberley Airvan operator making a forced landing on a highway a few seasons ago
We were all prepped about it before flying one!
The spiel was something like if you know you have plenty of fuel and the fuel guages agree, if the low fuel lights come on shortly followed by the low sump light, you have 11 minutes, slow for best endurance and land immediately.