We used this one.
https://www.pegasusautoracing.com/pr...s.asp?RecID=87

Yes, if the metal is hot enough.

http://www.skybrary.aero/index.php/Ignition_of_Fuels

fuel cell foam?
 

the Pegasus auto racing site also shows a yellow fuel cell foam that can be cut to any size and fit to fuel tanks.....albeit during construction for our tanks.

As I understand it dampens shock wave formation that causes tanks to explode, and slows leakage, and reduces combustible air/fuel vapour mixtures inside the tank. $54 for an 8x8x8" cube, E85 resistant.

Aim for water?
Uh-oh, here we go again....

Interesting. Thanks.

The problem with this stuff is it breaks down over time. Pegasus recommends changing it every 3 years because of the fact that it'll start clogging pumps and filters.

I have witnessed a decathalon that nosed over on landing with full tanks. The fuel simply leaked from the caps and vents and made a nice stream entering the cowl. There was no fire. Shutting off fuel would have had no effect in this situation. I know it is a high wing, but I think a similar outflow of fuel could happen in an RV sitting on its nose. Depending on how high the tail is, the fuel might reach a hot exhaust part. Just speculating, maybe somebody has seen an RV on its nose and can comment.

auto ignition temp of avgas 824?F / 440?C
 

ConocoPhillips
001769 - Aviation Gasoline, 100 LL
Date of Issue: 23-May-2007
Vapor Pressure: 5.5-7.0 psia (Reid VP) @ 100?F
Vapor Density (air=1): >1
Boiling Point/Range: 75-338?F / 24-170?C
Melting/Freezing Point: <-72?F / <-58?C
Partition Coefficient (n-octanol/water) (Kow): No data
Specific Gravity: 0.68-0.74 @ 60?F (15.6?C)
Bulk Density: 5.83 lbs/gal
Percent Volatile: 100%
Evaporation Rate (nBuAc=1): >1
Flash Point: <-35?F / <-37?C
Test Method: (estimate)
LEL (vol % in air): 1.5
UEL (vol % in air): 7.6
Autoignition Temperature: 824?F / 440?C

Stability: Stable under normal ambient and anticipated storage and handling conditions of temperature and pressure. Extremely
flammable liquid and vapor. Vapor can cause flash fire.

These inertia switches were used on all Ford vehicles with EFI throughout the 90's up to at least mid 2000's: http://www.sensata.com/download/resettable-crash.pdf I even installed one in my injected '66 GTO. Install it near your main solenoid/contactor in series with your existing main bus switch wiring.

Heinrich

Remember me I landed in the soccer field ? I hit that park sign going 60+mph and it sliced right into the fuel tank. Still waiting for the fuel tank to be repaired btw. But I was happy that no fire occurred. I did not get the fuel off before the landing admittedly.