Visit our Popular Forums

SvenG · 17-06-2010, 07:46

With old tanks I worry about what happens when/if our 80-gallon diesel tank should spring a leak. I've been monitoring channel 16 when a docked fishing boat had a tank burst and started pumping it overboard through a 2" bilge pump outlet, it did not sound pretty.

So, what can one do to prevent it ? I am looking to put a diesel filter in the bilge pump lines but that wouldn't handle gallons and gallons.

Ideas ?

-Sven

DeepFrz · 17-06-2010, 08:00

You are right, its not pretty. I've been in the vicinity (quickly vacated) when a gasoline tank leaked and the bilge pump started up.

The only suggestion I can think of is to make sure that your tanks and plumbing are in good shape. This is especially important in the more "modern" boats with almost no bilge sump.

**sandy daugherty** · 17-06-2010, 08:13

What was even less pretty would be the look on the owner's face when he get's the $10,000 to $50,000 fine.

Fix old tanks first.

Roy M · 17-06-2010, 08:35

West Marine (and other suppliers) have a variety of oil absorption pads and devices available. I place the pads and sausages in my customer's bilges, or under the engines and fuel tanks, to provide an early warning of potential leaks. Fuel leaks often begin with pinholes, then progressively deteriorate. The pads only collect the undesireable petroleum-based materials in the bilge water. There is no reason for any boater not to have these handy materials aboard. I call them "diesel diapers". In my yacht club's emergency locker we have several hundred lineal feet of Oil containment booms and a couple cases of absorbent pads for reducing the nasty effects of fuel leaks or sinking boats at the dock.

gonesail · 17-06-2010, 09:51

i have heard of leaks but they usually start as a trickle .. not a gusher. you would probably smell it before much went overboard.

cchesley · 17-06-2010, 10:36

If you're that concerned about pumping diesel overboard, I would think that it would motivate you to change out the tank before such a problem exists. Otherwise, it seems you're trying to solve a problem that won't really be a problem until you deal with the original problem... if you get my drift.

**Pete7** · 17-06-2010, 11:02

Having been onboard a Sigma 33 that had leaked her 20 year old fuel tank into the bilges I would do anything to avoid this. The smell was terrible, fuel has absorbed into the ply bulkheads, floor boards and run everywhere, oh and the owner was absent for many months before he tried to clean it up.

Despite being cheap I doubted I could ever clean it enough to get rid of that smell so happily walked away.

Our Moody was built by the same people who built Sigmas and our fuel tank is now 20 years old, so I am keeping a careful eye on it. Especially the inside were water would sit on the bottom of the tank rusting away unoticed.

Nice thick plastic is the answer especially for northern climes to cut down condensation in steel tanks.

Pete

anjou · 17-06-2010, 11:05

A very topical subject at the moment.

On the other hand, if your in the gulf it might help disperse the crude.

no?

Ok, im going now.

idpnd · 17-06-2010, 11:56

Quote:

Originally Posted by anjou

On the other hand, if your in the gulf it might help disperse the crude.

That's EXACTLY what I was going to say

Good luck with the project btw, enjoying your blog

boden36 · 17-06-2010, 23:37

Working from the fact that fuel is less dense than water, I wonder if you could weight a simple float switch so that it did not actuate in fuel, but did work in water? You may still have a problem with pumping at the interface. Regards, Richard.

Astrid · 18-06-2010, 00:44

Proper measure is Preventative Maintenance to keep it from happening in the first place. I would hate to be three hundred miles out from land and suddenly find my diesel fuel draining into the bilges. Make sure your tank is in good shape and cleaned out, then install a fuel polishing system that will circulate the fuel from the tank through filters and moisture separators and back to the tank again. This removes water, particulates and bio contamination even when the engine is not running.

**Pete7** · 18-06-2010, 00:56

Something like this then

We could have built it into the boat but decided to have it free standing and use it once a year to filter the tank instead. Pleased to report that after an hours run there was absolutely nothing to be seen in the filter.

Pete

SvenG · 18-06-2010, 19:08

I was actually expecting fewer "think of the children !" type replies and more of the "how to keep from pumping overboard" answers.

Any tank could spring a leak so having a way of detecting diesel in the bilge pump circuit seems like proper "leave only wakes behind" seamanship. A brand new or heavily sailed tank are probably most likely to spring a leak. I'd wager that a brand new tank is most likely to spring a catastrophic seam burst due to improper manufacture while an old one is more likely to spring a pin-hole leak due to age, vibration and corrosion. I do think (and hope) that an old tank pinhole would be detectable due to smell.

We have a mat of oil absorbent pads under the engine, we have to since we have a rock solid but supposedly drippy Perkins 4-108M.

Quote:

Working from the fact that fuel is less dense than water, I wonder if you could weight a simple float switch so that it did not actuate in fuel, but did work in water? You may still have a problem with pumping at the interface.

Thanks boden36, This is actually along the lines of what I was thinking too. Either that or using conductivity.

A few years ago there was a San Fransisco plan (now dead ?) to prohibit automatic bilge pumps to prevent pumping of oil into the bay water. BP notwithstanding, I can imagine other municipalities enacting similarly ignorant local codes and figuring out how to prevent the automatic pumping of oiled water is one way to stave it off.

As for oil or gasoline pumped into water we've suffered through that with remarkably lax local response: SSCA Discussion Board • View topic - Dana Point: When a significant spill isn't that big a deal ?

-Sven

Astrid · 18-06-2010, 19:40

Quote:

A brand new or heavily sailed tank are probably most likely to spring a leak. I'd wager that a brand new tank is most likely to spring a catastrophic seam burst due to improper manufacture

I believe proper manufacturers test their new fuel tanks under pressure to insure no leaks. They certainly don't want lawsuits or the EPA coming to their door. Now with older tanks, yes I can see the potential for a problem there. In such a case having a manually activated lower bilge pump and a float activated upper pump might save you from pumping leaking fuel overboard and allow you some time to get a fuel recovery plan into operation. If you are on board when the leak occurs, you should smell it easily enough. Much would depend on how much fuel you have in your tank at the time, but if you have a number of empty fuel containers you might be able to scavange fuel that leaks into the bilges. Going to be quite a mess though. Main thing is develop a plan or plans to suit your situation.