Fuel evaporation from wing tank?

[Richard]

I believe I've now heard everything. Some cat here told me 4 gallons per day can evaporate from a bladder on a C-207 at 4,300 msl with +35C OAT -08C Dew Point.

Sure there is some discharge of fuel vapor but what quanity could I expect to be lost through evap?

 

[SCCutler]

Richard:

It depends upon how much they are running the lawn mower.

 

[jesse]

I believe I've now heard everything. Some cat here told me 4 gallons per day can evaporate from a bladder on a C-207 at 4,300 msl with +35C OAT -08C Dew Point.

Sure there is some discharge of fuel vapor but what quanity could I expect to be lost through evap?

Sounds like something that would be pretty easy to measure...Measure and prove he is wrong--because he probably is.

 

[Dan Thomas]

I believe I've now heard everything. Some cat here told me 4 gallons per day can evaporate from a bladder on a C-207 at 4,300 msl with +35C OAT -08C Dew Point.

Sure there is some discharge of fuel vapor but what quanity could I expect to be lost through evap?

Just a little exaggeration there. 4 gallons per day from each bladder would leave the tanks empty in less than ten days. Don't think so. Cessna has a check valve on the vent line that lets air in quickly and out slowly to reduce fuel spillage and evaporation losses. Even if it was stuck wide open and both caps were leaking I don't think you'd lose anywhere near that.

Dan
________
Honda XL125

 

[Teller1900]

My bet is, he's siphoning 4 gallons a day from your tanks and that's just his way of explaining it away.

 

[JohnR]

Yeah, see if their lawn equipment has blue stains all over them.

 

[JHW]

return the favor - siphon 4 gal per day from his tanks, then when he says something tell him you'll have to concede his point that evaporation is real