What's it take to get my gas tank to swell?!!

[Billyzoom]

Holy cow!    C'mon, tank! 

I somehow keep getting all these scratches on my tank, but for some reason my tank is exceedingly stubborn and refuses to swell so I can get it replaced.  At my age I'm getting used to things not swelling like they used to, but this is ridiculous!   

Joel

[stopintime]

Fill it with water.

If that doesn't help, fill it with water and put it in the freezer.

(tank!)

[red baron]

Buy gas from California....

[kopfjäger]

Buy gas from California....

 . So glad I live in a state that's full of good ol boys. 

[teddy037.3]

dump some ethanol in it

[ute]

I'm with ya bud !!

scratch's and no swelling ....and I use 10% ethanol !!!!!  Damm 06 

[IdZer0]

From what I've read, don't ride for a long time and leave the gas in the tank.

[jerryz]

C4 or high pressure lines

[CairnsDuc]

Air Pressure, Just wrap your lips around the Exhaust and blow! 

[ducatiz]

Humidity.

I put E85 into a tank in a sealed cabinet with 5% humidity.  No swelling.

Same tank with E10, and I set the humidity to 75% = swelled within a month.

Ethanol can't do its evil unless there is enough moisture to suck it in.

Winter months are dry, lots of people in southern cal, arizona, new mexico will never see expansion.

Come summer and run that humidity up, you'll get plenty of condensation in the tank and ethanol will do its work.

The fuel testing in the Minnesota E20 test used a protocol requiring 50% humidity for those that are curious.  Their testing showed a 9-10% circumferential expansion in the test samples (e10 and e20).  I spoke with the guys who ran the test and they said the protocol was intended to simulate real-life fuel conditions -- they also added 1% water to the fuel mix.  However, given the reputation of Nylon-6 to absorb water that it was reasonable to assume most if not all of the expansion was due to the water/humidity and not the ethanol alone.