420: Transferring fuel from one tank to the other

[Fearnow]

Any ideas? If one engine dies on a passage, how would you transfer fuel over to the other tank?

[Cheechako]

You mean pump it? or why not just run the dead engine off the other tank, by valving the tanks to both engines?

[Fearnow]

I don't see any valve where you can run the working engine off the dead engine tank. This all occurred to me while on a passage, and I started thinking how I would switch the tanks without using a pump. I assumed there would be some sort of switch in the lines.

[Weyalan]

Sssuming that you are using diesel engines and that your 2 tanks are not already linked, I'd transfer the fuel from one tank to the other by transferring the first tank's "return hose" into the 2nd tank instead of the first. It would take a while, but would transfer the fuel from the first to the second

[leftbrainstuff]

Having some form of manifold will allow you to draw from or both and to feed back to one or both. This is simple to configure.

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[Boardshorts]

Our previous owner installed a fuel polisher with pump that easily lets you circulate/clean fuel within one tank or pump fuel between them. When refueling, we fill one tank and pump across rather than wrestle fuel hoses across the stern to reach the far tank.

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[rwidman]

Originally Posted by Fearnow

Any ideas? If one engine dies on a passage, how would you transfer fuel over to the other tank?

It really depends on how the tanks and fuel lines are set up. There's no one set answer to your question.

If you are unable to do this on your boat, you might want to make some modifications before you set out on that "passage".

[Fearnow]

You're right. The thought did occur to me while on a passage. If one engine goes down, couldn't figure out how I would transfer the fuel to the good engine. Can't believe there isn't a bypass valve to the two tanks.

[JeffBurright]

Simplest way I know is to make a siphon. Get one hose long enough to go from the bottom of the tank with fuel to the fill for the empty tank. Get a second hose that's 6" long or so to be your blow hose. Stick both hoses into the full tank, leaving the end of the blow hose out of the tank so you can access it. Wrap the hoses tightly with a damp rag to create a seal, then blow on the blow hose until your eyes cross. Once the flow starts moving, you should be able to take out the blow hose and have it continue without help. If your full tank is below your empty tank though, this may not work. In that event you could always use a Jabsco hand pump or something of the like to transfer fuel to a jerry jug.

[Scott Berg]

We have four fuel tanks (3 + a gravity daytank). Each is fed to a manifold (as are returns to each tank to a return one).

We can:

Polish fuel from a tank back to the same tank
Transfer fuel via a Filter from one tank to another
Draw fuel directly to the engine from any tank

Most cruising boats I've seen are similar.

In our case we tend to only take on fuel in one tank, add biocide, and then run it through our polisher into another tank. So far (touch wood) we've been able to handle bad fuel without cross contamination.

[Fearnow]

Thanks Jeff and Scott for your input. Good idea on siphoning to a lower tank. The tanks are at the same elevation, but may be able to run fuel from the tank to Jcan on the lower step. Scott, you have a great set up. Lagoon didn't get the memo on that one. I don't have any fuel polishing set up. Neve even thought about it. Figured the two filters would do the job. I will be spending most of my time in the Caribbean during the next two years and not sure if this is something I should be concerned about.

[hpeer]

You can buy a Whale Gulper from Northern Tool with Nitril bits making it suitable for transfer.

In the meantime you can set it up as a portable pump to pump just about anything anywhere. Pump out dingy, bilge, transfer from jerry cans, whatever. Put a filter on it and polish your fuel.

I use one to fill my day tank.

Whale Gulper 220 Diaphragm Pump — 3/4in. Ports, 200 GPH, 12 Volt Motor, Model# HD1552 | 12 Volt Pumps| Northern Tool + Equipment

[Cheechako]

I had 4 tanks on my Lagoon. I had added 2 before setting out ( don't need them though) I pumped to the main tanks with Walbro pump.

[rwidman]

Originally Posted by Fearnow

You're right. The thought did occur to me while on a passage. If one engine goes down, couldn't figure out how I would transfer the fuel to the good engine. Can't believe there isn't a bypass valve to the two tanks.

It would seem pretty simple to add a few valves to be able to run either engine from either tank or combine the tanks. Don't forget to account for the fuel return as well.

I think that's a better plan than hoses and siphons, especially if you are at sea.