Fuel tank leak- advice needed

[chuck g]

My 35-year-old sailboat seems to have a leak in its 30-gallon fuel tank, located inside the keel, which is seeping through the hull (photos attached). I believe it's an integral tank but won't know for sure until I drain the tank.

At this point I'm planning to come up with a temporary solution for the upcoming season, perhaps in the form of a 20-gallon plastic tank secured within available space in my engine compartment. Something along those lines may have to be my longer-term answer as well.

However, I've also wondering if I may be able to make use of the existing main tank, perhaps with an epoxy coating over the existing fiberglass or with a bladder or a fabricated tank. Unfortunately, access from above the tank is very limited.

Thanks in advance for any clear thinking--

[Terra Nova]

Assuming a f'glass keel, to properly repair an integral tank,you would need to cut/grind away the wall in the area that is leaking, cutting it back so that no fault remains, and taper the repair according to existing layup. Fuel is leaking out. And water would leak in. From here, it appears to have been caused by an accidental grounding. This is a straightforward repair that any full service yard can do.

As far as a makeshift work-around tank, fagetaboutit. Don't Mickey Mouse it. Do a seaworthy and workmanlike repair.

[colemj]

I don't know anything about your boat, its construction or how your tank is made, but something seems strange to me about this diagnosis.

First, I would be very surprised to see diesel leaking through a fiberglass layup in a keel area. Second, that thruhull at the bottom of the keel doesn't make sense to me - what is its purpose, and how is it related to the fuel tank?

It is really is a 30gal tank that is leaking through a thick fiberglass layup, then I would look for another place on the boat to install a permanent plastic 30gal tank, seal off the keel tank and forget about it. 30gal is small enough to not require baffles, so you can get an inexpensive tank to fit most any contour of an unused area.

Mark

[glenn.225]

Is that thruhull a drain for the tank or a drain for the bilge? When was plug taken out or opened?

Could it be that, the stain is just fuel creeping along the surface of the bottom paint, not an actual leak through the keel?

I think the tank will have to come out to fix or just drain it and seal the holes and forget it.

[Lepke]

A plastic tank in the engine room??? And if there is a fire you suddenly have 20 gallons of heated fuel for the fire. When I was young I saw a fire with a temporary tank near the engine. The owner didn't make it.

[chuck g]

The picture is of the aft end of the keel; the hole you see is the garboard drain with the plug removed. The dark stain is on both sides of the keel, including the one opposite the garboard plug, so I don't think it's just a case of bilge water existing the drain hole with some oil in it. Water beads up on the dark area, so I'm quite sure it's oil.

I have an empty 48-gallon rear fuel tank aft of the cockpit that hasn't been used in over a decade due to bad fuel. I'm starting to think I need to open it up, clean it out and turn it into my primary tank.

[Island_Moose]

While I couldn't sleep at night personally until I discovered how I had diesel fuel on my keel (!), I wouldn't stress about a poly day-tank in the engine room, which is what I have to save the weight of filling my main tank (I burn about 10gal/month). A fire large enough to melt a poly tank and ignite diesel fuel that isn't under compression would be one hell of a blaze, if you spring for a metal tank and have a fire like that, the tank might be the only thing you have left.

Now a poorly-restrained day tank is another matter...make sure it's not going to go anywhere even if you roll.

A Kiwi Nonsuch 30 Ultra: Fuel system

[Terra Nova]

Originally Posted by chuck g

...I have an empty 48-gallon rear fuel tank aft of the cockpit that hasn't been used in over a decade due to bad fuel. I'm starting to think I need to open it up, clean it out and turn it into my primary tank.

By all means! But you also have a leak to deal with.

[chuck g]

Update: after much thought and even more prep work, I added about an inch of Hebron 197 vinyl-ester resin (designed for fuel tank linings) and chopped mat to the bottom of my tank. It took time and patience and many awkward contortions, but all is well again with my main fuel tank. Thanks to all for the ideas and input!


Sent from my iPhone using Cruisers Sailing Forum

[deltaten]

Congrats on the rebuild. Well done!

Is Vinyl Esther related to Plasticene Pam??