Primarily for general aviation discussion, but other aviation topics are also welcome.
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By Miscellaneous
#1684052
With the Jodel we had a kit which, for want of a better description, had cotton buds which when placed in a fuel sample reacted with ethanol, if present, releasing a purple dye.

What are folks using these days, there doesn't seem to be much on the market to suit a quick check prior to putting the fuel in the aircraft.
By mr spog
#1684081
I use a method of adding a measured quantity of water dyed with food colouring. This is added to a measured quantity of the fuel and shaken. Any ethanol comes of the fuel and into the water. You can then measure the new volume of coloured water/ethanol and work out the percentage of ethanol from the increase. You will also need a measuring cylinder.
I have also asked all the local petrol stations what the % ethanol in their fuel was, and found the results of the above test to agree quite accurately with what they told me.
The method can be found on youtube, but I adapted it slightly.
Paul
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By Dave W
#1684087
Paul's method also works without the colouring - with water to a level you've noted in a fuel tester (or bottle/whatever) to which you then add some fuel.

The fuel sits on top of the water. If the water level apparently increases then ethanol was present in the fuel and is now in the water.

Note that the level won't increase dramatically, though - so take that into account when you decide what volume of fuel and water to test. Ethanol content if present is around 5% IIRC.
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By Miscellaneous
#1684096
Thanks, I like the method we use when fuelling the Jodel since it's easy and quick to use in a cold poorly lit hangar. The mixing with water is a little more fiddly, however I guess it is workable.

Although I have thought of asking the ethanol content I've assumed those serving would have no idea. Maybe I'm wrong? There's a newly refurbed fuel station due to open near the airfield next week, I'm hoping it's ethanol free, however I'd like to check. :D
By mr spog
#1684100
Its very unlikely to be ethanol free, they are nearly all 5%.
The only one I know that is ethanol free is a small supplier in the SE called Power (local fuels).
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By BobD
#1684185
Depending on where you are, this snippet from the Esso website might be relevant.

"Esso super unleaded petrol (Synergy Supreme+ Unleaded 97) is ethanol free (except in Devon, Cornwall, the Teesside area and Scotland). We would therefore advise anyone who has concerns about the presence of ethanol in petrol to use Synergy Supreme+ – providing they do not fill up in Devon or Cornwall, the Teesside area or Scotland."

Of course it shouldn't preclude testing, but may give you more confidence in fuel selection.

I don't work for Esso ! :)
By mr spog
#1684189
You are not advised to use the supreme types of fuel for Rotax etc. I can't remember the exact reason, but I think it's due to the different octane mix. As had been mentioned already, most unleaded in the UK is 5 % and Rotax allow up to 10% in more recent engines so it's not really a problem.
#1684195
mr spog wrote:You are not advised to use the supreme types of fuel for Rotax etc. I can't remember the exact reason, but I think it's due to the different octane mix. As had been mentioned already, most unleaded in the UK is 5 % and Rotax allow up to 10% in more recent engines so it's not really a problem.


Sorry but that is not correct information!
Rotax actually say you should use 97 octane in the 912uls, 100hp due to the high compression ratio (Esso brand it Supreme, other fuel brands have different names).
However in the Rotax 912ul, 80hp, which has a lower compression ratio they recommend 95 octane ( ordinary unleaded).
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By Sooty25
#1684197
It isn't just the engine that has to be considered though. My aeroplane has a Rotax and was cleared for MOGAS prior to the introduction of ethanol.

Whilst the fuel system has been completely rebuilt with ethanol friendly pipework and fittings, Ethanol will destroy the fibreglass fuel tanks!
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By ivor.phillips
#1684210
A requirement of my permit to fly is a sight tube, even using Tygon tubing that is supposed to be ethanol resistant (not Proof ) have had two fuel leaks after the tube has discoloured to the point of being useless as a sight tube, and hardened to the point that a leak occurred,
Using Avgas producers it’s own set of problems in a Rotax so will continue to use super unleaded as my airfield doesn’t want to supply UL91,
Any suggestions for a clear sight tube that is ethanol proof would be appreciated,
I don’t want to use a glass tube in the cockpit for obvious reasons,
By Iron Chicken
#1684352
ivor.phillips wrote:A requirement of my permit to fly is a sight tube, even using Tygon tubing that is supposed to be ethanol resistant (not Proof ) have had two fuel leaks after the tube has discoloured to the point of being useless as a sight tube, and hardened to the point that a leak occurred,
Using Avgas producers it’s own set of problems in a Rotax so will continue to use super unleaded as my airfield doesn’t want to supply UL91,
Any suggestions for a clear sight tube that is ethanol proof would be appreciated,
I don’t want to use a glass tube in the cockpit for obvious reasons,


How about a glass sight tube with a Tygon tubing cover. No discolouration and, if the glass tube were to be fractured it is contained and the Tygon will act as the sight tube until you can get the glass replaced.

IC
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By MikeW
#1684382
Polyurethane? That's what LAA suggests for clear fuel pipe.
There are many variants of Tygon made from a range of materials, I don't know which you have but I think the soft yellowish one is vinyl, but some Tygon is polyurethane.
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