Gasoline in the Diesel Tank?

[svHyLyte]

This past weekend a friend asked me to help him manage his boat on a short run to the fuel dock at our club. I did so and in short order we were back in his slip having added 26+ gallons of fuel to his tank without difficulty.

Yesterday he called me to ask if I had any doubt that he had added Diesel Fuel to his tank; and/or, if I knew whether gasoline and diesel would mix in a tank or stratify?

It seems that there was an error at the fuel dock at some point during the weekend with less fuel having been pumped from the diesel storage tanks than recorded and more gasoline having been pumped from the gasoline storage tanks than recorded, the over-count and under-count each corresponding to the exact amount of fuel he took on--26.4 gallons! If it was gasoline, it would have been mixed with about 14 gallons of diesel still in his tank which has a 40+/- gallon capacity.

Frankly, as I was simply a line-handler at the time, I didn't pay enough attention to the fueling to recall the colour of the fuel snozzle (green for desiel or black for gas). And I can think of arguments for both why the fuels would not stratify--as gas is such an agressive solvent; and, why they would--becuase of the relative densities. Has anyone a definative answer to that?

At this juncture he's going to pump out his tank to eliminate any doubts but I'd still like to know.

Thanks,

s/v HyLyte

[Sandero]

Can't he pump out enough to smell if has gas? The odors are very different.

jef
sv shiva

[hellosailor]

I'd expect them to mix pretty completely.

But is either the gasoline or the diesel at that dock dyed with a color?

It may be possible to pump out a quart or a gallon into a jar, and examine the color to see what it is.

You should also be able to test the specific gravity of the mix to find out what it is. Offhand, I don't know what gas or diesel is...but it should be possible to find out and then do some simple tests. Beer/brewmakers sell simple float testers, batteries and radiators are tested the same way...

26 gallons of gasoline on top of 14 gallons of diesel would NOT be a good thing for this engine. A couple of phone calls, to the gas distributors, to the local EPA or weights and measures people...one of them will probably be able to lend a hand and confirm what he's got, without any problems.

No sense dumping $120 worth of fuel unless it really IS contaminated.

From a fast web search:

7. Fuel oil no. 2 ... diesel fuel
flash point 126 degrees F-204 degrees F
(52 degrees C- 96 degrees C);
ignition temperature 494F (257C)
specific gravity less than 1

8. Gasoline -
flash point -45 degrees F (-43 degrees C);
ignition temp. 536 degrees F (280 degrees C) for 56 - 60 octane grade;
specific gravity 0.8;

I'm not sure if you could use the ignition points to tell 'em apart, but the specific gravity has a nice difference.

And for the more adventurous, with a candy thermometer and a stove:

http://www3.me.iastate.edu/me449_kon...Lab-3-fuel.pdf

Boiling Range
Product °C °F
Motor Gasoline 30 - 200 80 - 400
Kerosene, jet fuel 170 - 270 340 - 515
Diesel Fuel (#2) 180 - 340 350 - 650
Furnace Oil 180 - 340 350 - 650

If it boils before water does...it's probably gasoline. If it blows up before anything boils, it used to be gasoline.<G>

Apparently a web site exercise for identifying petroleum fractions, including how to set up the experiment.

[Alan Wheeler]

Yes the two mix and remain in suspension. They will not settle out into layers. Yes the Gasoline should smell and you should be able to detect it. You can also try igniting it. Not in the tank of course. Just a very small quantity in a shallow container like a bottle lid. Diesel is near impossible to ignite with a match. Petrol will burn quite easily from the mix. You can send it to a lab and have it tested. DO NOT run the engine.

[EngNate]

Originally Posted by hellosailor

26 gallons of gasoline on top of 14 gallons of diesel would NOT be a good thing for this engine.

ABSOLUTELY DARN RIGHT!!! THERE IS NO DEBATE YOU MUST DUMP ALL OF THIS FUEL!, Sorry, but you just have to do it. I've seen this happen - it was VERY Expensive.

USCG Designated Duty Engineer of motor vessels of not more than 500GT/1000HP (That's 1000HP @ 240 RPM)

[Sandero]

He doesn't know if it is contaminated yet.

jef
sv shiva

[EngNate]

Understood, he doesn't know for certain, but those numbers on the meters at the fuel dock do. I'd spend the $ for a lab test on lottery tickets and have better hopes of winning enough to pay for the fuel and disposal.

[svHyLyte]

For the sake of the exercise, my pal has mixed a pint of diesel with 2 pints of gasoline to see if they separate. (I doubt they will but who knows?). He's also tried the sniff test--"Smells like diesel"; and tomorrow we shall try drawing off a petri dish worth of the fuel to see if the vapours will light. (I shall report on the findings.)

Despite the foregoing, however, he has--wisely in my estimation--decided to pump the fuel out of the tank and send it to the recycle center run by the POL supplier to the Club. While this may solve his problem, in the event that he is not the victim, someone that fueled at the Club may be confronted with a nasty situation without forewarning unless everyone that thinks they took on diesel is notified ASAP. That could become an expensive proposition, either for the Club; or worse, for the victim.

Clearly more vigilence is needed by both fuel dock personnel but, particularly, the yacht owners. There, but for the grace...

Cheers,

s/v HyLyte

[Chief Engineer]

If it were me, in addition to sampling the fuel. I would send out the word any way I could to notify anyone who may have fueled up that day.

Where I am we have what I call the "coconut telegraph" once you tell a coupla people at one marina something of import...it spreads like wild fire.

Of course, in a perfect world, if I was the fuel dock operator...I would be proactive in trying to assist in getting to the bottom of this.

One suggestion I have is get some diesel fuel and some gas from the supplier. Compare the clours to what you sample outta the tank. As well as the sniff test.

[Starbuck]

That the amount of the pump overage agrees with what you took on is quite suspicious (but not quite conclusive).

The match should tell you a lot but no matter the results, I don't blame your friend a bit for recycling this & playing it safe. I know I'd feel better, even with thinner wallet.

[hellosailor]

"a petri dish worth of the fuel to see if the vapours will light."
Just remember, "FOOOMP!" followed by the smell of burning wool means your eyebrows were too close when you lit it. Don't ask me why I know this.
< G >

If he indeed got the gasoline mixed into his diesel, and he MOTORED AWAY from the dock?

Interesting point, how to make sure all of that is flushed from the lines and pump without running the engine--which might get very upset by the first taste of it. Opening the decompression lever and pumping it through unburned, I suppose, would be the easiest way to flush it all out? Using compressed air or manually activating the fuel pump, so as not to burn out the starter?

Either way, a batch of work that testing might show is/not necessary. Perhaps the club would consider adding a large "DIESEL" tag to one nozzle, and a similar "GAS" tag to the other, to reinforce the idea on those hot hazy days when minds wander.

[delmarrey]

Working with fuel sites, I can tell you that your first indicator will be the smell. With the ratio you discribed, the gasoline will be over whelming. It should smell like gasoline.

If it does, get it out of there as soon as possible. Most diesel boats don't have bilge blowers. And if so, hire a professional to pump it out then send the bill to the fuel dock. That's why THEY pay for insurance.

And DO NOT RUN THE MOTOR!

A VERY small amout of gas will not hurt a diesel but what you discribe can distroy a diesel motor.

[svHyLyte]

As a follow-up, my collegue and his crew are working on his boat as I type--being here at the office to tidy up a few matters.

FWIW--no one can smell gasoline at his filler valve. And, we motored from the fuel dock to his slip--albeit all of 10 minutes--with no indicators of anything amiss; and, I learned that earlier in the week he had motored out to the River to take part in a Club beer-can race; and, later, back to the Club, again with no indicators of anything amiss. He subsequently learned of the fuel dock discrepency from the Harbor Master who was trying to balance the Club's fuel records.

Given the suppoed amount of gasoline, it would seem that the problem would have become evident within a few minutes of starting his engine, no?

Regards,

s/v HyLyte

[delmarrey]

Originally Posted by svHyLyte

Given the suppoed amount of gasoline, it would seem that the problem would have become evident within a few minutes of starting his engine, no?

Yes! He would have been having problems as soon as the clean diesel had cleared the fuel lines. The motor would have started running erratically in a short time.

I susect all is well.

[hellosailor]

Could the error have come from someone manually transposing the two figures as they were writing down tallies? i.e. Someone "read" the gasoline meter, but logged it under the diesel column?