Keeping water out of my OB fuel

simonfraser said:
My fuel tank sits in the open on the rear deck, I can put a cover over it, but it's still going to get wet

I can add Wynn dry fuel, but is this a good idea long term ? How much per litre ?
Or fit a racor snapp in filter ?

What would you all suggest ?
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I would try to prevent water entering the tank. My tank has a vented filler cap, when necessary I loosely tie a plastic bag over the cap.

A water separator in the fuel line would be a good idea but not so easy to engineer with a portable tank.

The recommended dose rate for Wynn's Dry Fuel is 1 bottle full per full tank every 6 months http://www.wynns.uk.com/pTIS/GRP_CONS_DIESEL/71867_EN.pdf

 
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VicS said:
I would try to prevent water entering the tank. My tank has a vented filler cap, when necessary I loosely tie a plastic bag over the cap.

A water separator in the fuel line would be a good idea but not so easy to engineer with a portable tank.

The recommended dose rate for Wynn's Dry Fuel is 1 bottle full per full tank every 6 months http://www.wynns.uk.com/pTIS/GRP_CONS_DIESEL/71867_EN.pdf

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It's common over here to use methyl hydrate (wood alcohol) to break up water in gas (petrol) VicS.
I believe you will find the active ingredient in "fuel dryers" is MH.
It is available by the 3.78 ltr in our paint supply places for $10.
Never use Ethyl Gas(petrol) in any small engine. It sucks water out of the air & deposits it in fuel,causing a white jelly sludge to foul the carb bowl,jets & passageways. It is ok in autos because you normally burn a tank rapidly. But if it sits in a tank,carb. ,etc.,the ethyl separates from petrol after a month or two & causes real problems.
 
Len Ingalls said:
It's common over here to use methyl hydrate (wood alcohol) to break up water in gas (petrol) VicS.
I believe you will find the active ingredient in "fuel dryers" is MH.
It is available by the 3.78 ltr in our paint supply places for $10.
Never use Ethyl Gas(petrol) in any small engine. It sucks water out of the air & deposits it in fuel,causing a white jelly sludge to foul the carb bowl,jets & passageways. It is ok in autos because you normally burn a tank rapidly. But if it sits in a tank,carb. ,etc.,the ethyl separates from petrol after a month or two & causes real problems.
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Methanol!

But the main constituent of Wynns Dry Fuel seems to be propan-2-ol


AFAIK almost all petrol in the Uk contains 5% ethanol
 
If you're really that worried about water in the fuel, put in a filter with a water separator. I think though that you will then find that it isn't actually the problem that you thought...
 
I believe that most of the water which causes problems in carbs gets there by condensing in the carb, from the air.
I've fitted filters to small outboards, but rarely found any water in them.

I would fit some sort of cover to keep the spray off the top of the tank, assuming it's a normal portable tank drawing air into a vent on the cap.
If it's a fuel injection outboard, I'd fit a spin-on filter, we have those on the club ribs, not much water found at the end of the season, but no fuel probs with the outboards either.
 
VicS said:
Methanol!

But the main constituent of Wynns Dry Fuel seems to be propan-2-ol


AFAIK almost all petrol in the Uk contains 5% ethanol
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The more expensive stuff uses isopropanol (propan-2-ol)(rubbing alcohol over here) & is fine.
We used to have to use "gas line antifreeze" in our road vehicles at times,during winter,before ethanol gas arrived. Now "they" say it's not necessary-the ethanol in gas will keep it from freezing. I sill use methanol (gas line antifreeze) for freeze protection & getting rid of water-proportion 1oz/20L in everything except diesel.
Our hi octane gas is still ethanol free. After a few tanks of regular grade gas with "up to 7%" ethanol in seasonal/irregular use equipment,the crud build up became such a nuisance that most folks use only hi octane, ethanol free gas, in this equipment.
Ethanol gas should be used within 3 mos. ,according to gas companies. The ethanol separates & evaporates? by that time.
Whatever happens,ethanol gas is not good in rarely used eqpt. in my experience.
 
Len Ingalls said:
The more expensive stuff uses isopropanol (propan-2-ol)(rubbing alcohol over here) & is fine.
We used to have to use "gas line antifreeze" in our road vehicles at times,during winter,before ethanol gas arrived. Now "they" say it's not necessary-the ethanol in gas will keep it from freezing. I sill use methanol (gas line antifreeze) for freeze protection & getting rid of water-proportion 1oz/20L in everything except diesel.
Our hi octane gas is still ethanol free. After a few tanks of regular grade gas with "up to 7%" ethanol in seasonal/irregular use equipment,the crud build up became such a nuisance that most folks use only hi octane, ethanol free gas, in this equipment.
Ethanol gas should be used within 3 mos. ,according to gas companies. The ethanol separates & evaporates? by that time.
Whatever happens,ethanol gas is not good in rarely used eqpt. in my experience.
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Anyone have a view on whether using "Super" is a better idea than "Normal" for us UK small outboard users??
 
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Fantasie 19 said:
Anyone have a view on whether using "Super" is a better idea than "Normal" for us UK small outboard users??
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I use it for my strimmer which is a notorious thing for any fuel problems going. So far, so good.
It's hard to be definitively ethanol-free in the UK but spending the extra few shillings on BP's finest seems reasonable..
 
lw395 said:
I use it for my strimmer which is a notorious thing for any fuel problems going. So far, so good.
It's hard to be definitively ethanol-free in the UK but spending the extra few shillings on BP's finest seems reasonable..
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Agreed - the outboard mechanic I use advised me to avoid supermarket fuel - so I have - but I didn't consider super rather than normal...
 
Fantasie 19 said:
Agreed - the outboard mechanic I use advised me to avoid supermarket fuel - so I have - but I didn't consider super rather than normal...
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It seems very difficult to find out which fuels contain ethanol and which dont.

I found some info gathered back in 2011 . Most super grades did not contain ethanol then but there were regional variations. The situation could be different now 5 years on.

my main worry is the effect of ethanol on fuel hoses, diaphragms etc

The legislation is in place to allow ethanol to be increased to 10%. That will be a problem in many ways to owners of classic cars etc
 
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