I can not top off my diesel for winter. Problem?

[mdoyle]

I recently acquired my boat, and although I'm at least somewhat observant, I did not notice that all the pumps at the marina were gasoline. Now it is too late to run over to another marina and top off my tank before she comes out of the water.

I plan to treat with biocide, of course, but that's not going to help with condensation.

What can I do? Anyone have experience with this.

Oh, btw, I am in a cold climate and the condensation will likely freeze.

Cheers all,
Mike
Providence, RI

 

[Witzend]

The condensation is not the big enemy, the saturation of the fuel is. Best, just pump it dry and put fresh fuel in next season from a well attended truck stop.
Every year I topped off my tank only to find water in my separator next season, last year I pumped it dry, no more water in the separator.

 

[jsalley]

Jerry cans? How much diesel do you think you need?

 

[Rich Stidger]

I have topped off and also been half full for the winter in Bristol, RI. I have not had any problems with condensation either way. YMMV.

 

[mdoyle]

Fantastic, thanks to all.

I'm not sure how much I may need, but jerry cans it is. Might as well give that a shot - cheap fix and may as well play it safe if possible. Cheers Rich. It looks like I may not have to worry too much in our area if I can't pull this off.

Everyone have a great day,
Mike

 

[Bill1565]

Stock 37c tanks hold about 40 gallons, maybe a skosh more.

Fuel gauge hole in tank is very near fwd inboard corner. Three or 4 machine screws, carefully extract the float and you have access to the deep end. I made a siphon out of an outboard motor fuel line with a copper pipe stuffed in the end. By squeezing the bulb you can siphon whatever has collected in the deep end into a clear container and see if you have water. Lots of bulb squeezes to the gallon, but hey you shouldn't have gallons of water in there.

 

[31seahorse]

I agree with the idea of topping off the tank using 5/6 gallons at a time from a jug. We always carried a container of fuel on the deck so the jug will be usable for you next year. Additives can be put in there as needed to treat your tank of fuel. Plan to estimate how much fuel you need to fill up, but add the storage chemicals based on the full amount in the tank.

Draining the tank would be more complicated in my opinion. Condensation might occur in the empty space of the tank, and you would need to deal with the likelyhood of air in the fuel lines next spring.

Don't want to hold a fuel container up-side-down while you fill the tank? Siphoning works well. Don't want to risk a mouth full of diesel? Use two clear, soft plastic tubes into the top of your jug. One short one that you will blow into. One long one from the bottom of the jug and into the filler neck of your tank. (1)Set the jug at an appropriate place near the filler deck plate. (2)Insert the tubes as described above. (3)Seal the neck of the jug with a damp paper towel or similar small cloth. (Being damp may not be totally necessary, but it usually helped me make a good seal on the first try.) (4)Blow into the short tube to create pressure on the top of the fuel in your jug. (5)Watch the fuel flow. (6)After thefuel starts to flow the towel can be removed and used for drips/spills. (Stop the flow easily by pulling the long tube out of the fuel in the jug when the tank is full. Excess fuel can be drained back into the jug from the clear tube.)
(7) By planning ahead you can have small rubber stoppers handy to close off both ends of the long fuel tube to prevent dripping while the tube is in storage. It will be ready for the next time you want to add fuel in this way.

Phil

 

[Witzend]

I used an electric fuel pump switch wired to a 12 cigarette outlet. Run the hose in the sender hole, or the fill, depending on access. Takes just a few minutes. I use the old fuel in my home furnace, so no waste.

 

[CarlN]

I agree that the condensation worry is not the biggest worry. Your Racor will remove any condensation water before it bothers the engine. Stuff growing in the fuel from the condensate isn't a real big worry in the winter - too cold for the buggers.

Diesel fuel in the US ain't the diesel fuel of even five years ago. It's been completely reformulated for emissions. A whole bunch of additives that do get old. Starting with fresh fuel in the spring (make sure it hasn't sat in the marina's tanks all winter) is a great thing for your engine.

One of the best things I did with my boat was install a $50 pump and a few valves to make a polishing loop through the Racor.. During the winter, I visit the boat every couple of months. I add a small dose of biocide and give the fuel a nice two hour polish to get out any moisture. At launch, I add some of the FPPF Cetane and lubricity improver that Yanmar (Mack Boring) recommends, polish again and then top up with fresh fuel.

Carl