Fuel drain - water and colourless fuel
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Fuel drain - water and colourless fuel
The aircraft I'm flying has colourless fuel. If I do a fuel drain and there is a mixture of water and fuel, I'll be able to see a separation into layers (even though they are both colourless). But how can I tell if a sample without separation is all water or all fuel?
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You've got me curious. Running a diesel on heating oil?
Anyway, to the point.
Either add some non-water-soluble dye to the fuel or add a few drops of water to your sample would seem to solve your dilemma.
Anyway, to the point.
Either add some non-water-soluble dye to the fuel or add a few drops of water to your sample would seem to solve your dilemma.
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Water has a "surface tension", fuel does not, both look completely different if spilled onto concrete or tarmac or grass, water will collect in drops surrounded by dust, fuel will "disolve" into tarmac. They both taste completely different if you are not sure
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Flying something with a Thielert? We found the best way was to drop some water into the sample - condensation off an aircraft wing in the morning is a good start, or other sources. Unfortunately sniffing it doesn't work too well, unlike Avgas Jet A is pretty slow to evaporate, so the tester retains enough to smell strongly anyway.
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Yes, it's a Thielert. My friend suggested smelling it but (as madlandrover noted) fuel testers usually smell like fuel, whatever is in them 
Putting a few drops of water into the drain, or seeing how it behaves on the grass compared with water will do me nicely. Thanks all.
Putting a few drops of water into the drain, or seeing how it behaves on the grass compared with water will do me nicely. Thanks all.
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If there's any water in the fuel, you'll see a meniscus separating it from the water. Sometimes, the bottom of the fuel sampler will look like it's got bubbles in it, which are small globules of water. Of course, in the unlikely situation that you only get water in the sampler, sniffing may help, as would topping it up with fuel from the other tank's drain valve. It's highly unlikely that you'd get a lot of water in both tanks, so you should end up with enough fuel in the water to spot the difference.
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If you are really paranoid about water and want to be sure the sample is not 100% water, you could buy some "Kolor Kut" water indicating paste and apply it to say a lolly stick or similar that you insert in the fuel sample. Paste changes from yellow to red in the presence of water, stays yellow if sample is kero (or any oil).
Costs about Ģ8/tube but one tube should be sufficient for a couple of thousand tests if used correctly (ie sparingly!).
UK distributor can be found by googling "oilybits"
Costs about Ģ8/tube but one tube should be sufficient for a couple of thousand tests if used correctly (ie sparingly!).
UK distributor can be found by googling "oilybits"
