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Discussion Starter · #145 · (Edited)
I did read that pure aluminium will get corrosion points over the time. The aluminium I am using is called 5000-6000 series. It's a mix, there is magnesium in it to prevent corrosion. Some dude here tested aluminium with RE85. He had small tank, had RE85 sitting in it for a year, nothing happened to the tank inner surface. After 3 years the liquid started to look dirty.

I have russelperformance fuel lines, but those are over 12 years old, I dont know are those made for ethanol back then 🤔 the new ones are.
 

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Arouse the DAMPFHAMMER!
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Some dude here tested aluminium with RE85. He had small tank, had RE85 sitting in it for a year, nothing happened to the tank inner surface. After 3 years the liquid started to look dirty.
Thanks for sharing this experience. What does the R in RE85 stand for?

Basically it is like @drtye mentioned it, there are two types of corrosion: water driven and alcohol driven corrosion. But there is an aluminum oxide layer hindering or retard massively those processes. You can measure the pH-value of your fuel tank, between 4 (acid) and 8.5 (slightly base sided) the corrosion mechanism are very slow working. There are measures available to reduce it, kind of fuel management or just leave it and check the fuel and the filter from time to time. @Lotus does quite often use E85, not sure if he has an Alu tank. Maybe he shares his experience here too.
 

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I use e85 in a ProAlloy made aluminum tank.
I even asked the manufacturer beforehand. They said it is no problem as long as the fuel is actually used up at some point. They advised against filling it up with e85 for winter storage. I use our ARAL 102 Octane fuel for winter storage.

Now it comes in handy that I am actually a chemist.
Aluminium corrosion from ethanol fuels is a well studied topic. The rates are highly dependent on water content.
Without the presence of water in the fuel system, very little to about nothing happens. That is until someone adds strong acids or bases into their fuel tank.
But why would anyone do that except with the intend to destroy their fuel system.


In closed fuel systems typical fuel injected cars, very litte water gets into the fuel. The only source is essentially the temperature induced “breathing“ of a partly filled or empty fuel tank. Fuel tanks warms up during daytime, air escapes the fuel system though its ventilation system, charcoal canister etc. During the night, it cools down again, air contracts, pressure drops and moist outside air is sucked back in.
E85 can hold a lot of water before puddling. As long as you use the fuel within days or weeks, nothing happens as the water is “transported“ away by plainly consuming it. In long term storage, it is bad as the water accumulates. Carb bowls are the worst as they are essentially open through the needle seats and bowl overflows. e85 is hygroscopic, draws in a LOT of water during winter storage (motorbikes, lawn mowers) and the carb internally corrodes. Zinc die cast is almost worst than aluminium alloys. Magentsium is also affected. It forms alcoholates, essentially salts, that in the presence of water for crosslinked polymerates in the form of gels, commonly called sludge. They do not dissolve in anything but strong acids and bases. You carb dissolves faster….

To cut the chase short. e85 is no problem as long as the fuel is regularly used up.
For winter storage, use low to no ethanol fuels. For motorcycles or lawn mowers, drain the carbs before storage. Completely fill up metal gas tanks before winter storage.
 

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Arouse the DAMPFHAMMER!
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To cut the chase short. e85 is no problem as long as the fuel is regularly used up.
For winter storage, use low to no ethanol fuels. For motorcycles or lawn mowers, drain the carbs before storage. Completely fill up metal gas tanks before winter storage.
Thanks for the reply and experience on your side on that 🆙.
 

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Discussion Starter · #159 · (Edited)
It fitted great, now I can see where to weld/cut the top part. Tank will be about 1-2cm higher than in the pic.

I work in aluminium foundry, and we sent some parts to anodizing for better duration in outdoor use. I was wondering should I send the tank for anodizing too.

Grey Asphalt Rectangle Road surface Wood
 

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Arouse the DAMPFHAMMER!
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I was wondering should I send the tank for anodizing too.
The controlled oxidation during a maybe Type 2 anodization process (Sulphuric based) definitely would be an advantage regarding el. insulation, corrosion resistance and so on.
 
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