How do I reduce fuel evaporation

[hutch]

Every weekend I am blow away by the amount of fuel in my 73 that has evaporated.  At first I thouht someone was sucking the gas out of my tank but its locked up in my garage and I live in the middle of BFE.  A week ago I topped it off 10 miles from my house then locked her up.  Over the 4th I took it up the road to get topped off and I figure about 5 gallons up and went missing someplace.  Anyone else have that issue with stored cars?

[craigandlynda]

after the car is in the garage and cools down, very carefully and thoroghly search under the car for a drip...a steady drip will drain your tank, and if slow enough, will evaporate without leaving a trace on the floor...use a flashlite (NOT a droplite you could acccidentally break and create a spark) and examine all the lines around the tank...use dry tissue paper to feel around on top of lines and fitings where you can't see well...old lines and hoses can leak out a lot of gas over a weekend, and you won't see anything on your floor...look for "wet spots" in the undercoating and dirt around the lines...also check any vent canisters' bottoms...somewhere, your gas is leaking slow enough to evaporate without easily observed evidence.

[1969chargerrtse]

after the car is in the garage and cools down, very carefully and thoroughly search under the car for a drip...a steady drip will drain your tank, and if slow enough, will evaporate without leaving a trace on the floor...use a flashlite (NOT a droplite you could accidentally break and create a spark) and examine all the lines around the tank...use dry tissue paper to feel around on top of lines and fittings where you can't see well...old lines and hoses can leak out a lot of gas over a weekend, and you won't see anything on your floor...look for "wet spots" in the undercoating and dirt around the lines...also check any vent canister's bottoms...somewhere, your gas is leaking slow enough to evaporate without easily observed evidence.

Dang!  That was really informative. 

[Big Lebowski]

  Sucks dont it, but don't plug the vent lines or else the pressure will collapse the tank, or more commonly actually cause a leak from the pressure on the sending unit seal or the filler neck seal.

[hutch]

you know i never even thought about it being a drip because I never saw anything on the ground.  Here I am asking about evaporation of gas and let that one slip past me.    I have some news paper under the tank now after I read this reply and that should help me track it down. 

Thanks guy.

[Steve P.]

Also keep an eye on your oil dip-stick. A bad fuel pump or some crap on your carbs needle and seat could dump fuel into your motor. Sniff around and you will find it...