Gas tank drain plug?

[Paul G]

A tank of gas lasts me months with no problems.

[terrible one]

10% Ethanol breaks down/ seperates after 30-90 days. I can think of more reasons to spend the $5 for a bung and plug and weld it in while you are already replacing the tank than I can think of not to.  

Where did you get this info ?  I have ran 2 year old Gas with 10% and never had a problem.  

This is based on my experience with gas going stale after a semester in school (About 3 months, but this was just in a 5 gallon gas can in the shop area, admittedly different than a mostly sealed fuel tank), in addition to the fact that ethanol is hygroscopic and will bond with water molecules more readily than the gasoline molecules. Of course there are plenty of factors that contribute to how long it takes for E10 to break down, this is just what I consider a good period to go by. But the fact is that ethanol attracts water and once there is enough of it it will seperate from the gasoline and bond with the water, it's called phase seperation, which you can read some more on here: http://fuelschool.blogspot.com/2009/02/phase-separation-in-ethanol-blended.html

[ACUDANUT]

My father just told me he had a problem with his gas in a 5 gallon can (after 6 months of storage)..Seems strange because there is not alot of air left in that small tank to allow deterioration.??

[Tilar]

You could easily add a "T" somewhere in the fuel line that is plugged and when you are ready to drain the tank, Hook up an electric pump where the plug is and suck it out. That way you don't have to worry about a thin tank leaking where you modified it.

[b5blue]

  I mostly want to do it to know it's bone dry if/when I drop it for trunk repairs or knowing it will sit for more than 2-3 months. The fuel that sat since last Oct. burned OK when mixed 50-50 with new in my Jeep. Now that the car is back on the road I'll not let it sit for more than 5 days without running it for now. I'm saving up for a new high quality tank and will buy a new drain bung. It's going to be awhile before I get to it. (Keep in mind the plan would be to drain it when it's darn near empty.)

[terrible one]

My father just told me he had a problem with his gas in a 5 gallon can (after 6 months of storage)..Seems strange because there is not alot of air left in that small tank to allow deterioration.??

Agreed, and that is probably a big factor, how full the gas can/ tank is . . . I know one thing, I'll never forget the smell of rotten gas 

[b5blue]

  The tank will drain itself if you disconnect the feed line to the fuel pump, extend it out to a container and use siphon action buy keeping the end of the extension bottomed in the container. That's how I verified free flow from the tank to the fuel pump and removed 5 gallons.
  The problem is the fuel pickup still leaves a good measure of fuel in the tank. That last gallon or so would rot faster due to all the air in the tank. The drain would remove the very last bit if placed correctly.