Best Material For Custom Fuel Tank

[Woodnaut]

A few years ago I had a pair of aluminum custom gas tanks made by Atlantic Coastal Welding. They did a good job all around. I have another potential application for what will definitely be a CUSTOM gas tank and was trying to decide on the best material.

The boat is mostly used in saltwater, so I'm hesitant to consider steel. Aluminum is fine for ethanol blends up to 10%. My concern is that most of the fuel in this area is already 10% ethanol and I'm concerned that before too much longer E85 might be creeping in. Everything I've heard is that aluminum is NOT acceptable for E85. So I guess that just leaves stainless - and probably 316 SST at that. Am I missing something here? Also, how much more expensive is SST over ALUM? 50%? 100%?

[JB]

Dunno about the cost of making it, Woodnaut, but the long term cost of making it out of the wrong stuff is incalculable.

I would bite the bullet and use Stainless.

[jlaudio29]

It is essential to know that some materials react negatively when they are combined with high alcohol content fuel. For instance, car materials such as zinc, lead, aluminum, and brass are sensitive metals that degrade in the existence of a high-content alcohol mixture. Other sensitive materials include lead-based solder and Terne-plated steel (composed of lead, tin, and alloy). Both are commonly used as fuel tanks for gasoline. Bronze, black iron, stainless steel, and unplated steel are also sensitive to high-content alcohol mixture

says stainless in there not sure taht is a good material either

[jlaudio29]

http://www.epa.gov/reg3wcmd/Ethanol_...Final_Rev3.pdf

page 28.. says stainless AND aluminum are acceptable?

seems to be a lot of misinformation either way in my opinion. and im sure you could find some e85 safe fuel tank sealer, so you could build it out of aluminum and then coat the inside with the sealer.

[Coors]

Plastic?

[redfury]

Plastic?

I was going to say the same thing. You can have plastic tanks made easily. I have one I'm replacing the old steely with, though mine is blow mold injection vs. fused panel construction. I guess it would really depend to me as to what kind of plastic being used and how it breaks down over time vs stainless steel. Stainless should last the life of the boat realistically, plastic can break down to UV light, chemicals leeching into it and breaking it down internally, etc depending on what it's made out of ( Assuming they know how to make a proper fuel tank ).

My only other concern would be the ability of the plastic tank to take the roughhousing a boat can see beating into waves, etc. What can happen over the long run.

To me, a fuel tank is one area you just make sure fits your application and never scrimp on it.

[Coors]

I agree, but the auto peeps seem to be using plastic, knowing that nasty e85 is coming.
That crap will eat everything up in a boat, with storage, etc.