Salt crystals in fuel tank

[halfmoon]

After second fuel polishing, I was given a jar of clear particles recovered from the polisher's filters. First thought from trusted mechanic was polymer lining or leak patch deteriorating. Decided to test particles. Put some into two solvents.
1. Acetone: Particles were cleaned of diesel residue, but remained solid.
2. Warm water: Particles quickly dissolved.
Had my fuel been sabotaged?
Fired up campstove and placed a few crystals into tin cup. Crystals remained intact, no burning or "caramelization." So, I think I have salt crystals in the fuel. Plan to enjoy this weekend's 70 degree weather by pumping all the fuel out of my tank.
Has anyone had an experience like this? The fuel polisher said he had never seen such particles before. Any chemists out there with simple tests to differentiate between Aluminum and Sodium salts?

[jleonard]

I could see how it would be conceivable to suck in sea water thru the tank vents depending on how they are arranged. I would make sure the vent openings are not anywhere near the wake or bow spray areas.
But no other than sending fuel to a oil analysis lab (why don't you do this?) I don't know how to test for salt vs Al.

I do know of a gas boatowner who salted up his carburetors and the suspicion was that the salt was in his fuel via the vents

[Serenity]

When Serenity was winterized, the marina sent oil and fres water coolant samples to Caterpillar for fluid analysis. When I received the reports I had asked the yard what all the numbers meant and they did not know. (Sounds like my blood work) I called up Caterpillar and spoke to a tech who told me that they could not possibly come up with a scale for every diesel out there. However, what was important, if there were any comments in regard to the test results. They only comment was "Sodium NA is elevated". Their reccomendation was to change the air filter and the air intake system. There were no other issues with the oil. HO Penn did go on to state that I should change the oil in 50 hours and the oil retested. Since salt air is entering the fuel system through the air filter, and any unused fuel is returned to the fuel tank, is it possible this could be a cause for salt crystalls ion your tank?

[RobS]

Interesting post Max. I wonder if those "infamous" forward facing hull-side vents for the engine room are cause for salty air ingestion.

[Russell]

I think it is unlikely that any salt water that enters the air intake could contaminate the fuel in the tank. The air will be mixed with fuel injected into the cylinders. The excess fuel that is not injected returns to the tank so there should be no way it would come in contact with the salty air. You may recall a turbo wash where a cup of soap water is poured into the air intake and this does not go into the fuel tank.
Some sea water splashing on the tank vents might be the source and may be worth an inspection to see that they are installed correctly. The previous owner may have left the fuel cap loose and got sea water in without realizing it. If any of the salt crystals are pulled out of the tank they should end up in the bottom of the Racor fuel filter. There is a bolt on the bottom of the Racor to drain water and other impurities. I replaced the bolt with a stop cock sold for that purpose and periodically drain out a little water and some black stuff.

[Serenity]

Just a thought. I have a Yanmar., with NA in my oil.

[RobS]

The fuel returned to the tank starts it's trip back to the tank at the injectors. Any salty air injested would only mix with the fuel injected into the combustion chamber. I dont think that salt in the combustion chamber would go anywhere but with the exhaust but I could be wrong..

[N4QC]

A second opinion, as to salt air getting into the fuel tank via the return fuel from the injectors, will hold water (pun intended), only if the return fuel line allows the fuel to exit below the level of the fuel in the tank. In my case the return fuel line ends at a point, at most times, above the fuel level in the tank. I believe it causes much surface contact of the heated return fuel to the cooler tank fuel, with the return fuel displacing and making contact with the ambient salt air in the tank. This might be construed as some type of cooking procedure: add salt and stir…

Further, as the level of fuel in the fuel tank is adjusted by fuel use, heated fuel return, and ambient temperatures of air in and outside the tank, the volume of outside salt air within the tank will also change. The source of entry for the air inside the tank normally would be the air vent for the tank. The air vent air can be conditioned by the use of a desiccant air filter. I have not seen them on a boat but they are used on fuel oil storage tanks.

Happy searching,

[Russell]

You can check this link that says there is no salt in air: http://wiki.answers.com/Q/Why_is_there_ ... in_the_air
Somehow salt water has gotten into the fuel tank and the most likely source is through a loose fuel cap or the air vents that are constantly splashed with salt water when running in rough conditions.

[halfmoon]

Finally removed transom bench seat and attached deck. Easier than I thought. Removed most of fuel, but transfer pump jammed. Opened it to find large salt particle as culprit. Photos are of salt particles I picked off the floor of the tank. Now plan to remove all fuel and wash tank with water. Still can't figure out how these particles formed. Have posted on BOAT DIESEL also.

[halfmoon]

Trusted consultant found posting on "the hull truth" which incriminated the fuel treatment Biobor. Salt crystals found in fuel system of that boat were exactly the same as mine.

[seasalt]

It is my understanding that when my boat was relatively new the fuel vents had to be relocated because of very significant water ingestion into the fuel tanks. The vents were located on each side about an inch forward of the transom. At certain running angles and speeds they sucked water into the tanks causing a shutdown. It seems logical that at other speeds salt vapor could enter the tanks. The new vents are on the sides about even with the back of the cabin.

In this case, however, more than salt crystals got in. So much water that the tanks had to be cleaned. I have opening ports on top of each tank to allow cleaning and dual Racors for each engine.