Replacement Fuel tank - Plastic?

[Jim Cornwell]

Yankee's fuel tank leaked diesel into the bilge within minutes of launch. Prompt battery installation activated the bilge pump. And, well, everyone knows what happened next. Fortunately, quick action prevented a major disaster and saved the day. So now this 8-year-old welded 1/8" aluminum, epoxy coated tank from a reputable fabricator has to be replaced. It's been suggested that a polyethylene tank might be a cost-effective alternative to aluminum. Cost-effective? Hmmm. Any experience? Any thoughts?

[mgphl52]

I would suggest searching Moeller tanks. They make a enormous number of shapes & sizes.
Once you locate a model or 2 that will work for you, go a-googling on the model number(s) for the best price.

[Capt Hook]

I think Jim Walsh had a replacement fuel tank fabricated for his CD 31. Perhaps he will chime in from Bermuda if he's still there and has wi-fi.

[Jim Cornwell]

Thanks for the suggestions, folks! Moeller does have a splendid variety of polyethylene tanks. I had no idea! But, to fit the space available, I'd have to settle for a 14 gallon tank, 5 gallons less than the original and three gallons less than the prematurely ruptured 17 gallon one. So a custom-fabricated aluminum tank it will have to be, from Atlantic Coastal Welding. More unanticipated boat bucks....

[Doug Gibson]

I replaced the tank in my CD36 about 4 years ago. I used Luther's Welding in Bristol RI. They had built replacement tanks for CD36 before. Very happy with quality. Total cost, including shipping to west coast, was cheaper than any local options.

I'm curious if you know where/how leak occurred on your tank. 8 years is definitely premature.

When I pulled my old tank out, I found it sat in a fiberglass pan with no limber holes, so any water that got into pan remained. It had about 8" of water/diesel in it! The tank had about 10 locations where corrosion allowed fuel to seep through. You could push a pencil though! But is was 25 years old.

I drilled limber holes at the lowest location of the pan and glued 1/8" plastic strips to the tank bottom and sides to act as stand-offs to allow air to circulate (and water to drain) between tank and pan. The limber holes are 3-4" above the bottom of bilge sump.

[Jim Cornwell]

Well, Doug, that's the very question I'm waiting for an opinion about from the BoatUS surveyor! The tank was nicely made and properly installed on a resilient bed and it showed no signs of corrosion. It's epoxy coating was blistered in the immediate vicinity of the small crack but perfectly intact elsewhere. If I get an answer, I'll post it here. Yankee's previous tank, original, I believe, had also been welded aluminum. It failed dramatically when a wood screw, projecting slightly up through the plywood shelf supporting the tank in the port cockpit locker, worried its way through the aluminum. It took over twenty years, but it finally drained the fuel completely on my shakedown cruise/delivery voyage on a moonless, windless night well off the coast of New Jersey. "We're sure going through a lot of diesel," the naive new skipper thought to himself in the inky darkness....

[Vincent]

I am going to buy a Moeller water tank. It will be the 1st of three new tanks. I know this thread is about fuel, but if the water tank is solid ,I will go with a Moeller fuel tank as well. The same size Kracor was over $600. The Moeller is $120. I will post once I get it from Jamestown .

[Jim Cornwell]

The official word on Yankee's failed tank from the underwriter's surveyor is that the leak was caused by corrosion from the inside. Despite fuel stabilization and despite careful attention paid to exclusion of water, I only got 7 seasons out of it (one of which included the extended layup, of course - which might be the culprit). Corrosion, not surprisingly, is among the hazards excluded from coverage. So a new 17 gallon aluminum tank is due for delivery "any day now." A Moeller plastic tank would have been much less costly, but only a 14 gallon size would fit the space available. Too much of a capacity sacrifice, I concluded. I think Cape Dory built the boat around the old 19-20 gallon tank - the fit was so tight it had to be sawzalled out. Next winter, I'm thinking, all remaining diesel will be pumped out, with a fresh start in the spring. Thoughts on this strategy?

[Jim Walsh]

My original aluminum tank failed after 24 seasons. It had a few pinhole leaks in the bottom of the tank. My tank was mounted on a plywood shelf and held in place with a teak cleat. It slid into a recess which held it securely on all sides, but, it still had a "belly band" attached with a lag bolt which was only accessible from under the sink in the head.
I brought the tank to Luthers in Bristol R.I. because of their reputation. I asked for a direct replacement and stressed that there could be no dimensional variance whatsoever. The replacement was a perfect match and it was exactly 20 gallon capacity as was the original.
I mounted it on a few strips of Treadmaster to ensure the tank did not make solid contact with the plywood shelf and there would be some way for moisture/air to circulate.