Ethanol free petrol

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catalac08

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Having looked at some of the concerns people have about the effect on seals, fibreglass tanks, metals and particularly corrosive exhaust residues of ethanol in petrol it would seem to make sense for me to use straight petrol in my main engine outboard. It seems difficult to ascertain which main petrol brands have or do not have bio-ethanol in them.
Any informed views on this subject, either sources of non-bio petrol or knowledge of the effects of bio petrol on boat engines?
 
catalac08 said:
Having looked at some of the concerns people have about the effect on seals, fibreglass tanks, metals and particularly corrosive exhaust residues of ethanol in petrol it would seem to make sense for me to use straight petrol in my main engine outboard. It seems difficult to ascertain which main petrol brands have or do not have bio-ethanol in them.
Any informed views on this subject, either sources of non-bio petrol or knowledge of the effects of bio petrol on boat engines?
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As far as I'm aware what's currently sold in the UK contains 5% ethanol and is set to increase to 10% this year ... I don't think you can buy ethanol free petrol anymore, just like you can't buy leaded.
 
Agreed, commercially available petrol contains a percentage of bio fuel by law. It is highly unlikely that that anything below 10% will harm your fuel system or engine.
 
rafiki_ said:
Agreed, commercially available petrol contains a percentage of bio fuel by law. It is highly unlikely that that anything below 10% will harm your fuel system or engine.
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Its interesting, as a fuel retailer we are suffering an increased level of seal failure in our pumps. Pumpouts are around 200% up since bio-fuel came out. And our pump service engineers, Tokheim have confirmed its a national problem.... not what the fuel companies want folk to know.
 
Firefly625 said:
Its interesting, as a fuel retailer we are suffering an increased level of seal failure in our pumps. Pumpouts are around 200% up since bio-fuel came out. And our pump service engineers, Tokheim have confirmed its a national problem.... not what the fuel companies want folk to know.
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Interesting point, but not sure of the relevance wrt the OP. Your pumps are dispensing thousands of litres a week. An outboard engine, tens of litres every now and again. Duty cycle is totally different.

Out of interest, can you get natural rubber seals for your pumps? Natural rubber is much more resilient to ethanol.
 
Have a look at the classic car scene, there will be problems with higher ethanol petrol with some cars less than 20 years old! As far as I am aware the ethanol content will be on the petrol pump by law if it is more than, I think, 10%. Super unleaded should be ok. There are problems looming.
 
will that stuff make any difference to the corrosive nature of alcohol? I think it will attack brass, aluminium and some rubbers.
 
rafiki_ said:
Interesting point, but not sure of the relevance wrt the OP. Your pumps are dispensing thousands of litres a week. An outboard engine, tens of litres every now and again. Duty cycle is totally different.

.
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but they are immersed in the stuff for the same length of time!
 
I think that the main problem that is lurking here is for owners of RIBS or similar craft with GRP petrol tanks.
According to my sources ethanol over time, eats into standard GRP gelcoat/ flowcoat so the tanks will become porous?
Be very interested to hear if anyone can confirm or refute?
 
Pennpromo said:
I think that the main problem that is lurking here is for owners of RIBS or similar craft with GRP petrol tanks.
According to my sources ethanol over time, eats into standard GRP gelcoat/ flowcoat so the tanks will become porous?
Be very interested to hear if anyone can confirm or refute?
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I would be interested to hear of anyone with a recent approved fuel tank made of GRP for petrol rather than diesel - we found it hard enough to find anyone to approve a resin for use with the current diesel fuel.
 
No out board I have ever dealt with had its fuel pipe drain back intentionally when off. Would make starting difficult,with carbs and especially modern injection engines, as there would be perhaps problems with small air bubbles etc

carburettor bowl, evaporate to dry, but the rest of the system remain wet. Nor with cars mowers etc. In fact the only thing That drys its plumbing I can think of is the ad blue circuit on a modern truck, and you hear them back pumping when turned off. be interesting to hear of systems that do, aircraft, for heat vapor lock problems?
 
Rubber - resistance to bio-ethanol fuels, or not actually..

rafiki_ said:
Interesting point, but not sure of the relevance wrt the OP. Your pumps are dispensing thousands of litres a week. An outboard engine, tens of litres every now and again. Duty cycle is totally different.

Out of interest, can you get natural rubber seals for your pumps? Natural rubber is much more resilient to ethanol.
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I am afraid natural rubber is not resistant to ethanol blends

The blending of bio-ethanol with petrol [gasoline] are a real challenge to us in the rubber industry attempting to provide seals and hoses with adequate resistance to these fuels. E5 [5% ethanol] is currently available in the UK and E10 10% ethanol is on the way this year. All rubber components in the fuel delivery system need to be changed to fluoroelastomers [Dupont's Viton is the most recognised trade name] however these need to be specifically blended to cope with the different mix ratios available and it is a real minefield at present with no flexible sealing materials exhibiting a really satisfactory long working life.

See http://wwwt.dupontelastomers.com/literature/viton/06ACSMini-Stevens.pdf for further reading.

It also leaches resins from GRP fuel tanks and although some epoxy coatings are better than polyester resins I have no doubt it will become a major problem.

I have a GRP moulded-in tank in my 45 year old boat, the bottom of the tank is the bottom of the hull. which has been fine till now but I am about to cut out all the molded in baffling so that I can insert a flexible bag tank inside as a liner as I don't fancy the structural integrty of the bottom of the boat being compromised, plus I don't wan't to risk losing 100 gallons of finest super unleaded to the deep....
 
I find it interesting, and somewhat amusing, that a lot of people worry about the effects of ethanol on their various mechanical toys yet will quite happily shove it down their own necks most weekends without a thought of the damage to themselves. :confused:
 
GRP Tanks

Paul,
I do think it's a problem that's lurking and not really appreciated. I take on board what you say about Viton and we only ever use that for tank gaskets for petrol.
Natural rubber goes all soft and gooey in no time. A Lot of epoxies should be Ethanol resistant but unless I am mistaken isn't ethanol one of the main constituents of paint stripper? Says it all really! If you use say Nitromores on GRP it takes off the gelcoat, (yes I have done it!), Diluent does not contain ethanol so is safe. SIMON

Scarron said:
I am afraid natural rubber is not resistant to ethanol blends

The blending of bio-ethanol with petrol [gasoline] are a real challenge to us in the rubber industry attempting to provide seals and hoses with adequate resistance to these fuels. E5 [5% ethanol] is currently available in the UK and E10 10% ethanol is on the way this year. All rubber components in the fuel delivery system need to be changed to fluoroelastomers [Dupont's Viton is the most recognised trade name] however these need to be specifically blended to cope with the different mix ratios available and it is a real minefield at present with no flexible sealing materials exhibiting a really satisfactory long working life.

See http://wwwt.dupontelastomers.com/literature/viton/06ACSMini-Stevens.pdf for further reading.

It also leaches resins from GRP fuel tanks and although some epoxy coatings are better than polyester resins I have no doubt it will become a major problem.

I have a GRP moulded-in tank in my 45 year old boat, the bottom of the tank is the bottom of the hull. which has been fine till now but I am about to cut out all the molded in baffling so that I can insert a flexible bag tank inside as a liner as I don't fancy the structural integrty of the bottom of the boat being compromised, plus I don't wan't to risk losing 100 gallons of finest super unleaded to the deep....
Click to expand...
 
Scarron said:
I have a GRP moulded-in tank in my 45 year old boat, the bottom of the tank is the bottom of the hull. which has been fine till now but I am about to cut out all the molded in baffling so that I can insert a flexible bag tank inside as a liner as I don't fancy the structural integrty of the bottom of the boat being compromised, plus I don't wan't to risk losing 100 gallons of finest super unleaded to the deep....
Click to expand...

Yes, there are certainly some problems that will need to be resolved on many older petrol boats, when insurers /surveyors consider the looming risk. I considered getting a custom flexible bag made up for the integral (grp / ply) tanks in my Settimo Velo but couldn't find a supplier that would make them (with a guarantee) for use with petrol containing ethanol. There were suppliers out there doing flex tanks for diesel, but not for E5/10. Also, whilst integral tanks are considered fine for diesel they are not recommended for petrol ... and cutting the baffles out may lead to some structural issues under weight of fuel? It's a problem well worth resolving for brilliant classic petrol powered boats like the Triana. I cut my old tanks out in the end (horrible job!) and put in new custom aluminium.
 
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