Bluer than Normal

[richas]

Yesterday, when I sampled fuel before flying, my lower right gascolator produced fuel that was very blue compared to the others, any idea why? The tank on that side was lower on fuel than normal, five gallons.


Rich

PA22/20 160HP

 

[Henning]

It's not always the same, sometimes deeper blue, sometimes paler. So long as it tastes ok it's good.

 

[Silvaire]

Check for leakage, may not be enough to actually drip but as fuel seeps out and evaporates the dye gets left behind then gets flushed into your sample cup.

 

[richas]

Check for leakage, may not be enough to actually drip but as fuel seeps out and evaporates the dye gets left behind then gets flushed into your sample cup.

That seems the most likely culprit. I'll check it out.

Thanks

Rich

 

[Fearless Tower]

Also, keep in mind the blue is just a dye....so the shade can vary between fuel sources.

 

[Henning]

Also, keep in mind the blue is just a dye....so the shade can vary between fuel sources.

I notice it all the time. Sometimes the blue is so pale I have to look through it at a white surface to tell.

 

[Silvaire]

That may be true but I believe he is talking about the sample being very dark blue (I've seen this before myself) and all of the fuel being from the same source.

Is the gascolator stained? That would indicate a leak.

 

[richas]

That may be true but I believe he is talking about the sample being very dark blue (I've seen this before myself) and all of the fuel being from the same source.

Is the gascolator stained? That would indicate a leak.

Yes, all the fuel was from the same source. I will check for leaks the next time I can make it out to the aerodrome.

Not sure how fuel can leak out but leave the dye behind.

Rich

 

[JOhnH]

It's not always the same, sometimes deeper blue, sometimes paler. So long as it tastes ok it's good.

So you drink the stuff? That certainly explains a lot.

 

[Henning]

Yes, all the fuel was from the same source. I will check for leaks the next time I can make it out to the aerodrome.

Not sure how fuel can leak out but leave the dye behind.

Rich

What happens on a slow weep is the volatiles evaporate away before it drips and the dye remains behind in the drain spout. Pour fresh fuel through it and it picks up the residue.

 

[Geico266]

So you drink the stuff? That certainly explains a lot.

No silly, he just gargles with it.

 

[ebetancourt]

Maybe the fuel evaporates faster than the dye?

 

[denverpilot]

We saw similar when our bladder let go in the left wing... there had been a small leak up there somewhere that wasn't being seen during inspections.

When enough fuel finally hit it, it washed the dye residue down with the new fuel and the blue staining was strong. Same thing with a worn out fuel line between the tank and cabin in the wing root. Dark blue.

 

[NineThreeKilo]

I've noticed when sumping tanks with older 100ll it tends to be a little more blue.

 

[Jim_R]

Yes, all the fuel was from the same source. I will check for leaks the next time I can make it out to the aerodrome.

Before taking the sample, try running your finger along the bottom part of the quick drain (where drips would fall off, if it were dripping) and (a) see if it's moist and (b) see if your finger comes away blue.

Either or both are signs of a small leak there. It's generally pretty easy and inexpensive to swap out those QDs. Just be careful about the spilled fuel that's an inevitable part of the process.

 

[Henning]

Running your finger is not the best piece of advice to give as it begs for trans-dermal absorption on unknown quantities of concentrated TEL, at least advise to use a gloved finger.