Steel or Poly?

Heater hose is not fuel rated. Should work for a while, but that's not an application that it's recommended for.

 

Huh. That's the opposite of what I would expect. I had thought that tank rust-through was due to liquid water puddling in the bottom of a tank of gasoline. That's what water will do if the tank is full of pure gasoline. Pure ethanol is hygroscopic, that is, it will absorb moisture directly from the air. Ethanol will also dissolve in both water and gasoline, due to its 'detergent' (bipolar) character. I would think that the tendency for this fuel to keep water in solution rather than it puddling out would inhibit corrosion, not promote it.

 

In smaller quantities it does that great. Most fuel line drier products are ethanol for that very reason. The problem is when the quantity of alcohol is increased too much it brings in much more moisture into the tank then the water absorbed can separate in the tank and condense on the inside of the tank or puddle on the bottom. I'm not sure of all the chemistry involved but I think it may have something to do with heating and cooling cycles of the fuel through ambient temperature and the sloshing of the fuel when driven. What I do know for sure from experience is that we have far more rust issues in the steel tanks in the last 10 years here than we ever had previously and I know it's directly related to the fuel and the alcohol content. In the Pacific Northwest we have pretty poor quality control when it comes to the fuels sold and the alcohol content can run pretty high in many of them. One of our normal drivability tests when so much alcohol was first introduced into our fuels was a test for quantity of alcohol in the fuel as it was causing real issues. There was even a Ford Motor Company Technical Service Bulletin listing fuel brands to avoid and others that were recommended because of this.
I think the amount of rain and humidity we have and the sudden weather changes have an effect also. We've had such sudden temp and humidity changes I've actually watched water form on my tools in my tool box. This may not be near as much of an issue in a drier climate though or an area where so much alcohol is not in the fuel.