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Return to the Forum List Safety Alert on the use of E10 ethanol fuel | This Safety Alert on the use ethanol fuel was taken from the web site of the TYA of NSW and ACT. If you wish further information go into their web site and click on safety requirements and then further info.
ETHANOL ALERT: Boat-owners are advised to avoid the use of the E10 ethanol fuel blend because of a corrosion reaction with fibreglass and aluminium fuel tanks and fuel lines with rubber components.
There's a risk of fuel leaks and onboard fires. E10 has been known to absorb moisture which sinks to the bottom of the tank, creating a separation of fuel and water and ultimately a major problem which involves draining, cleaning and drying the entire fuel system, including carburettors and electronic fuel injection components.
Marine industry authorities in Victoria, New South Wales and Queensland have advised their members to avoid the use of E10.
THE SUNDAY MAIL May 17, 2009 Page 79
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| | Re: Safety Alert on the use of E10 ethanol fuel | Thanks for that warning Alistair. The effect on synthetic rubber fuel lines has been well publicized but I hadn't thought about its effect on tanks.
The bit about it absorbing moisture and separating is not true though. We used to add alcohol to fuel tanks that had free water in the bottom and the water would be absorbed by the alcohol which all mixed with the fuel and passed harmlessly through the engine. So I think it acts opposite to what is claimed here in that, when it absorbs water, all three components (fuel, alcohol and water) mix provided the water proportion is small.
This only worked if the water was clean though. The water layer seems to hold any contaminants in the tank and forcing that to mix with the fuel just clogged filters.
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| | Re: Safety Alert on the use of E10 ethanol fuel | E10 has been known to absorb moisture which sinks to the bottom of the tank
Ethanol, chemically an alcohol, readily soaks up water. However, generally, the problem with water in the bottom of the tank is associated with leaving the tank overnight part filled. This invites condensation via the breather vent and airspace and the condensate then sinks to the bottom of the tank. Solution is one of
(a) empty the tank periodically to get rid of the all the rubbish. Naturally enough this is only suitable for small, portable tanks.
(b) install a low spot drain point to do likewise much more easily with a larger tank installation
(c) routinely run the tank down to empty or near empty so that the rubbish is moved along regularly and routine fuel line filter changes avoid the engine failure problem.
The bit about it absorbing moisture and separating is not true though.
Petrol fuels are a problem with water due to the water's settling out to the lower points of the system. Diesel/jet fuel, on the other hand readily permits the uptake of small water globules - eventually settles out again but takes a lot longer than for petrol.
Certainly a problem in the flying game and much effort is made to remove the water prior to flight for various reasons - engine failure, carriage of any rubbish into the mechanicals, freezing at altitude, etc.
We used to add alcohol to fuel tanks that had free water in the bottom and the water would be absorbed by the alcohol which all mixed with the fuel and passed harmlessly through the engine.
Standard chemistry - alcohols grab water - so, for instance, if one has an external ear infection associated with water (ex-swimming etc) the GP may prescribe alcohol ear drops to get rid of the residual water hiding away in the recesses. The mixture going through the engine gives some extra oomph to the process - again an aviation analogy - larger engines used to achieve power augmentation by means of added water (increased mass flow) and methanol (for some balancing of the burning bits)
The water layer seems to hold any contaminants in the tank and forcing that to mix with the fuel just clogged filters.
Again, with an aviation analogy, fuel systems have drain facilities to allow one to get rid of any water and assorted gunk - far better than having it go downstream. Guess it's not quite so critical with small boat tanks which can be emptied out easily. Always causes me to roll my eyes up with fixed installations as putting in, say, an aircraft fuel drain is in the realms of child's play and the fuel contamination issues can be made to disappear.
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| | Re: Safety Alert on the use of E10 ethanol fuel | Gents
Like you, I raised my eye brows at some of the statements and I was surprised that they did not mention the fact that unlike the old super leaded petrol, old E10 and unleaded petrol if left in the tank too long can go stale and this can create starting and operating problems in some outboards.
I am now aware of this problem (I learnt the hard way, no safety alert) and I now mix my own two stroke fuel in 10 litre lots using only the more costly premium unleaded petrol and I then use this batch in my 2 stroke lawnmower as well my 2 stroke outboards. I take this 10 litre tank with me every time I go out in the boat to top up the tank and I make sure that I give the engine a bit of throttle and a good workout before raising the sails.
I feel everyone should be made aware that any water making its way into any fuel or lubricating oil tank from any source can generate a bacterial/fungal growth inside the tank. This creates a slime that blocks fuel filters and if the problem is not addressed ‘quick smart’ can cause major damage and corrosion to the tank and the engines fuel injection system and the bearing journals, if the contamination reaches the lubricating oil.
Apparently the most common microbiological organism found in the fuel is Cladosporium Resinae and this can propagate and grow rapidly mainly in diesel and kerosene fuel and lubricating oil tanks if there is an oil and water interface level in that tank or sump. The rate of propagation is usually increased in warm and humid climates.
Until I was prompted by John and I googled the CR organism, I was not aware that our marine fungi was also a problem in aircraft fuel tanks (now that is a real worry)! They call it the ‘kerosene fungi’ and we apparently call it the ‘diesel bug’.
Nulon has technical bulletin on the diesel bug and they say:
• Keep the fuel tanks full (no condensation).
• Drain water from the bottom of the fuel tank (Bacteria cannot survive without water).
• Protect the tank from any possible water ingress. (Check the O ring on the deck filling plug).
• Purchase fuel from large volume sites (fuel is fresher).
• Purchase if possible from a reputable supplier.
• Avoid purchasing fuel that has been recently delivered. (This will allow the agitated water and contaminates to settle).
The Yanmar Marine Engine web site recommends using a biocide and it is noted that some reputable oil companies supply hydraulic oil with a biocide already in the oil.
With regard to water getting into petrol tanks, I remember having this problem once and it was eventually traced to water in an underground tank in my local petrol station. This was confirmed when they used water finding paste on the tank dipstick. I never went back to that petrol station and I solved the problem with the car by pouring 1 litre of methylated spirits into the petrol tank once a month for three months. I am not wowser really, but I think it is easier to purchase meths and it might do the same job as the whisky!!!
There is an old saying that water and oil do not mix and it is used when the mates and the engineers on the ship are not getting on! The ability of different fuels and water to settle out and create an interface in tanks is based on the different specific gravity of the particular fuel in relation to water. I think sea water is 1.025, fresh water is 1 with heavy fuel oil being around 0.95 and Marine diesel 0.87 with petrol coming in at around 0.7. The bigger the difference the quicker a fuel/water interface will appear. In the old days we steam heated our dirty HFO (3 % sulphur) in our storage tanks on motor ships to help the pumping process before transferring it up to a large settling tank with a hopper bottom.
After more steam heating and after the HFO has had time for the water and other contaminates to settle out and be drained into the sludge tank, the HFO is then centrifuged in high speed separators to remove any other water or solids and sent to a heated daily service tank. It is now ready to be used in the main engine after the temperature of the fuel is adjusted to ensure the HFO is at the correct viscosity for injection into the diesel engine.
I like safety alerts and I am in favour of this safety alert. Over the years I have witnessed some strange happenings when using and mixing similar fuels from different sources. It is a known fact that some not so ethical overseas oil refiners have been dumping unwanted carcinogenic nasties and other unwanted oil waste from their refineries into the HFO supplied to ships! The worst period for this was during the international fuel crisis in 1973.
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| | Re: Safety Alert on the use of E10 ethanol fuel | ... can generate a bacterial/fungal growth inside the tank.
A major concern for jet aircraft. Mostly, we rely on QA in the manufacturing and distribution systems to keep us reasonably safe.
They call it the ‘kerosene fungi’ and we apparently call it the ‘diesel bug’.
Jet fuel is kerosene and diesel, I gather, is one fraction oilier than kero.
• Avoid purchasing fuel that has been recently delivered. (This will allow the agitated water and contaminates to settle).
Kero/diesel can take quite a few hours to settle enough water out of suspension after agitation to see the two fluids. For this reason, petrol engined aircraft routinely use a visual check of water (doesn't form a suspension) in a drained sample while jet aircraft have to use a water paste or similar as a visual looksee is useless. Simple to see the difference - add a small quantity of water to a fuel sample in a glass or suitable plastic container and agitate for a few seconds.
This was confirmed when they used water finding paste on the tank dipstick.
We use a shelf lifed water detector. If anyone would like a time expired sample to play with let me know and I will send some to you when we restock.
by pouring 1 litre of methylated spirits into the petrol tank
again, an alcohol
the different specific gravity of the particular fuel in relation to water.
I learn something new every day - had never given it any thought before.
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