Aluminum gas tank

The topic of e-10 gas in a new aluminum tank came up at a club meeting. Does it need a sealer? Is fuel treatment the only thing needed? Does it need anything at all ?

Mick

Aluminum of tank thickness is essentially a non issue with dilute cold ethanol, about same as water in it, so definitely some oxidation surface reactions towards a light anodizing to sapphire layer, but not so ya can tell.

I imagine all of the aluminum gas tanks that are available are made with an 1100 aluminum alloy which is basically pure aluminum. Pure aluminum has excellent corrosion resistant qualities. It immediately forms an aluminum oxide when it is exposed to the atmosphere which actually seals and protects the aluminum underneath. I have a BSAA 441 Victor with an aluminum tank and it is still bright and shiny inside like the day it was manufactured. I have been using ethanol based fuels in this tank for quite some time.

About the only thing I can say negative about aluminum tanks is that being pure aluminum they are easily dented. However, I have owned my BSA for over 20 years and have yet to put a dent in it. Another thing is that like most tanks if they are not isolated from the motorcycle vibration they will crack.

Aluminium tanks should be rubber mounted. If they touch the frame they can beat a hole in themselves. Also if cables are bent underneath them they can wear a groove through vibration. Corrosion is pretty much a non-issue. The only things which will always cause damage are alkaline solutions and mercury. You don't usually have those in your tank. You could find that if you leave petrol with a water layer under it in the tank for a long time, organisms such as aspergillus niger and cladosporium resinae can grow and cause damage. The aircraft people know about this. I always use methanol fuel and my tank and carburetors are usually dry when I'm not using the bike. If there are dissimilar metals involved, the white slime can grow, especially in the carburetors where it can block jets. Rust in a steel tank is a worse problem.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC546914/

Alan I ain't worried about bio flim clogs nor tarnishing alloy but where does one buy gas tank fulls of methanol fuel?

Any company which supplies racing fuel usually keeps methanol. I always use it if racing, however in a road bike it is too much trouble. For racing it usually makes jetting less critical - the margin for error is doubled, unless you are running it extremely lean.

acotrel said:

Any company which supplies racing fuel usually keeps methanol. I always use it if racing, however in a road bike it is too much trouble. For racing it usually makes jetting less critical - the margin for error is doubled, unless you are running it extremely lean.

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You keep forgetting that not everywhere allows methanol for racing.

PeterJoe said:

Pure aluminum has excellent corrosion resistant qualities. It immediately forms an aluminum oxide when it is exposed to the atmosphere which actually seals and protects the aluminum underneath.

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AFAIK Aluminium oxide is actually not resistant to ethanol and the passivated layer is slowly "eaten up" by the ethanol. The term for the product is alkoxide and allthough the process is not really fast and therefore not that obvious this is the reason e.g. that a lot of first generation VW direct injection engines from about ten years ago were not approved for E-fuels when these went on sale here in Germany a few years ago - they have aluminium fittings and fuel pumps which VW fears that the might be harmed by E-fuels.

I'm not a chemist so I don't know how relevant this is but at least the statement that there is no problem with alu and E-fuels is not true.


Tim

Dave, In Australia we are allowed to use methanol in bikes made before 1973. My Seeley 850 gets into that class on a cheat, however I would not think of racing a four stroke using petrol. Methanol is much gentler on engines even though it usually makes them go faster. A two stroke on methanol is a beautiful thing because it chills the crankcases. In a 4 lap race, you usually get three fast laps, on the last you have brake fade and a slower motor. The funny thing about methanol is that in the 50s every racer was using it, and it was probably the reason our guys competed so well in Europe - they were used to the speeds. However when they got there, they found out that the manxes in Europe using petrol, went as fast as the ones in Australia which used methanol.
Personally I don't like petrol for racing, I believe product reliability is an issue. I think that is why a lot of our top guys use Elf Racing fuel. This thing about having ethanol in the petrol is appalling if there is no readily available alternative. In Australia we've removed the TEL however the benzene is still there, so it is still toxic and I think I'd rather become more mentally retarded through exposure to lead than get leukaemia from benzene.

So, the general opinion is that the e-10 is OK for the aluminum tank? This one was made in England by Bartels, I got it from Mike Partridge at Waldridge motors, a well made tank at a good price.
I always use the stabilizer with a fill up.
I had one made here: http://www.roccitycafe.com/store.php -and ran it last year on my 75 MK3, no sigh on any deterioration. I drained the tank and carbs for the off season.

Mick