Old diesel

obiec · #1 (**permalink**) 02-18-2003

My Boat has 10 year old diesel in it, I am only using it through the cabin heater to try and get rid of it but it puts of an oder. also it is leaving crust in the boattom of the berner. I am hoppin that this is all becase of the old diesel. anybody have any thoughts.

jnj · #2 (**permalink**) 10-30-2006

Old diesel fuel and fuel stabilizers. I believe that any fuel left in the tank over winter and added to in the summer needs to be occasionally changed only because of the incidences of gunk I've cleaned out over the years in gas powered lawn mowers and air compressors left standing over the winter. However, a boat lying in active waters for the season should stir the liquid enough to keep the bacteria (i.e. gunk, dirt etc.) suspended and moving toward the fuel filter. Three years ago at the beginning of the season I had the remaining 8-10 gallons of diesel fuel pumped out of the tank in our 20 year old sailboat boat thinking this act set the stage for another 20 years of reliable service. Most fellow sailors eschewed this precaution as inconsequential to reliable engine performance but, unlike the tankfulls of gas in your car that are replaced weekly or sooner, diesel fuel doesn't seem to be so refined a liquid that it rejuvenates itself by the introduction of a few gallons of newer fuel each spring.
This brings up the subject of fuel stabilizers. Each year I buy a new $8-$13 bottle of diesel fuel stabilizer because I haven't done my homework to confirm that the remaining 90% in last years' bottle will still be effective. To further erode my certainty about the integrity of the stabilizer even more, last week when I went to my local West Marine store for a bottle of stabilizer the clerk assured me their supply of Biobar Diesel Stabilizer "just arrived today". Not one of the newly arrived Biobar bottles was sealed. Only a free-wheeling top protected the elements from being some-how contaminated. Other manufacturers tops were sealed however I never see an expiration date so are they last years leftovers or "just arrived". Does anyone know the shelf life of these stabilizers and can you just keep adding stabilizer to the treated fuel remaining in hte tank? Thanks

Valdare · #3 (**permalink**) 10-31-2006

I was told by my mechanic I could add the stabilizer every year but only to the amount of fuel I added. Since I rarely use and entire tank in a season, I would add stabilizer equal to the amount of full I used to top off the tank no more. I am in the great lakes so we are on the hard from Nov to April. Been five years and have had no problems to date.

John

hellosailor · #4 (**permalink**) 10-31-2006

"U.S. Borax Service Bulletin, No. 978, Biobar.RTM. JF Fuel Fungicide. "

Apparently there are many products with many similar spellings. If you mean "Biobar" that apparently is just a fungicide. I'd be surprised if that was shipped without a positive seal, but like most other toxins a plain bottle cap probably is all it needs. You don't go looking for a "fresh" bottle of DDT or dioxin, do you?

AFAIK this is not stabilizer of any kind, it is just fungicide.

The crust could be almost anything after ten years. Tiny critters, dissolved rubber fittings? Who knows. Almost anything will burn well enough for heating as long as it doesn't cause clogs and you're willing to clean. "Pump" fuels, at least in the US, are designed to be used within 90 days maximum. After that, they degrade. Good enough to make heat...but a good tank & line cleaning once every decade isn't really asking a LOT, is it?

JakeLevi · #5 (**permalink**) 11-01-2006

If your boat has ten yr old diesel in it you are at least 8 years overdue for a pump out and system flushing.

LyleRussell · #6 (**permalink**) 11-01-2006

We have "sucked off the bottom" every spring and get a pint or two of discolored funky diesel fuel before it bocomes clean. We use a long thin copper pipe with a clear segment and the oil changer suction tool. Also we add biocide every time we put diesel in the tank. In a good year our boat won't use a tank of fuel.

Yes we use a stabilizer. But we don't buy a fresh one every year.

No problems so far.

jnj · #7 (**permalink**) 11-25-2006

Thanks for your collective stance on the shelf life of fungicides. Considering I used an ounce from a new bottle every year that we've had this boat I've got enough to do the entire marina for the next two years.
P.S. sorry for the late response.

Goodnewsboy · #8 (**permalink**) 11-26-2006

I use a rule that diesel fuel more than a year old should be rotated to oil burner stock. (I suck it out with my Oilboy and put it in my home heating oil tank.)

That said, contamination of diesel fuel by microbes is a more serious matter, and it pays to use a biocide before you have a problem.