Leaking Fuel Tank

[Harv1941]

We have a 54 foot Bluewater Aft Cabin Motor Yacht, one of only 12 built to order by Bluewater company. Our yacht was built in 1988 and has been a good live aboard since we acquired her in 2016! However a health issue has caused us to prepare the old girl for sale to another owner. During our projects to check out and correct any deficiencies prior to any surveys we discovered that the fuel tank (500 gallon aluminum tank) which is covered by a fiberglass shell had sprung a small leak. We had been quoted up to as much as 55 thousand dollars and considerable ripping out of structure to remove and replace this tank. Another source suggested we consider inserting a bladder into the old tank. No cost forecast with that option as yet.

Questions has anyone experienced a leaking tank of this size and what did you do. Consider the bladder option and if so what was the result? Since we cannot afford the total remove and replace our options are bladder insertion if feasible or setting the old girl up for scrapping.

Thoughts, suggestions are most welcome and solicited. We had a potential buyer but I cannot in good conscience sell them a boat with such a huge outlay as this. When we bought the old girl in 2016 we lost the starboard engine due to catastrophic water failure. We don’t want to saddle anyone else with a huge outlay as we encountered.

[thinwater]

Most likely the tank is heavily corroded and a welded repair is impractical. The type of encasement can also make welding impractical. Another possibility is sandblasting followed by installation of a supported (fiberglass cloth) resin liner. This is common in underground storage tanks.

This won't be cheap, but should be many times less than the quoted price. Access will be required and baffles will need to be cut down, but it can be done. The baffles will need to be removed for a bladder as well, so that's going to happen either way. (Licensed API tank inspector)


The best vendors are probably gasoline tank repair contractors, not marine guys.


Best wishes.

[Harv1941]

Thank you for the reply. A marine broker friend today recommended a boat yard owner near Annapolis who might be able to recommend a solution. Hoping I can get information like yours who have been there done that. Many thanks. We really hate giving up on our dream of live aboard and cruising but had at least four years. Some never get that.

[Tayana42]

My 1989 sailboat has two diesel tanks of black iron, 65 gallons each. One developed a leak. After exploring other alternatives I had a bladder custom made and inserted in the existing tank.

Same problem of inaccessibility for removal of the tank without demolishing the interior of the cabin. In addition to opening up the top of the tank you have to remove any baffles in the tank and grind them down smooth so as not to have any chafe on the bladder. I also padded the inside of the iron tank with rubber decking tiles before inserting the bladder. You want a high quality bladder tank builder to manufacture one to the exact dimensions of the inside of your existing tank so you need to measure the rhomboid shaped tank very carefully.


I used Aero Tec Laboratories, Inc.
Spear Road
Ramsey, New Jersey 07440
201-825-1400
ATL@ATLINC.COM

Cost was $1296 in 2004. That was in addition to the cost of grinding out the baffles in the iron tank and installing the bladder.

Your tanks are bigger but the process should be similar. Best of luck with your repair.

[Harv1941]

Originally Posted by Tayana42

My 1989 sailboat has two diesel tanks of black iron, 65 gallons each. One developed a leak. After exploring other alternatives I had a bladder custom made and inserted in the existing tank.

Same problem of inaccessibility for removal of the tank without demolishing the interior of the cabin. In addition to opening up the top of the tank you have to remove any baffles in the tank and grind them down smooth so as not to have any chafe on the bladder. I also padded the inside of the iron tank with rubber decking tiles before inserting the bladder. You want a high quality bladder tank builder to manufacture one to the exact dimensions of the inside of your existing tank so you need to measure the rhomboid shaped tank very carefully.


I used Aero Tec Laboratories, Inc.
Spear Road
Ramsey, New Jersey 07440
201-825-1400
ATL@ATLINC.COM

Cost was $1296 in 2004. That was in addition to the cost of grinding out the baffles in the iron tank and installing the bladder.

Your tanks are bigger but the process should be similar. Best of luck with your repair.

Thank you for the information. I will certainly inquire about the Aero Tec Lab. I believe I read something of theirs during my Google Search. The boat yard that I was directed to for the problem has from all indicators, several installations of bladders in tanks. The marine techs who were working on my boat when the leak was identified believe that the major leak damage came from some idiot in the past using the fiberglass shell as a point to attach a cable tray and multiple screws inserted of which some probably penetrated the tank. However, they also found some leakage on the port side of the system. So, the idea of ripping up the fiberglass top will have to be performed anyway. We are now at the point of deciding (based on the total cost to repair the tank) whether the repair will be offset by any potential buyers. Since we cannot continue living aboard the Misty Lady, we either find a buyer or take her to a salvage yard for dismantling. Sadly, she has a significant number of valuable components, including two Cat Diesel main engines (750 total horsepower), one Westerbeake 20kv genset and one Westerbeakle 10kv genset. Her command electronics were upgraded to a single Multi-Function Display command station, a new radar set, a tracking satellite dish with with connective system components supporting two television sets. She has a washer and a dryer, a new dishwasher, and other improvements over the past four years to make her a more comfortable home for my wife, myself and our two sea cats. Unfortunately, when one's health goes south, the need to move back on land becomes no longer an option, but a necessity. A major instance bringing this home is that 10 days ago, I took a spill on the finger dock alongside our home, breaking four ribs. At 78 it takes a lot longer to heal that when I was 28. So, we opted to fix the look of the old girl's inside and make her more attractive to someone else. Found an interested young couple, and then after spending several thousand dollars on presentation view for our cabin walls (three sleeping cabins, three heads, a full galley, large salon and some 1000 sq feet of living space, the leaking fuel tank showed it's ugly face and we were taken aback at the preliminary estimates to repair the tank. There is probably still some 400 gallons inside the tank and obviously this would have to be removed and stored.

I truly thank you for the information, especially your "been there done that" experience. So happy we found this forum shortly after we bought out water borne home. Learned a lot from the experiences of the posters here, similar to your information sharing.
Best
Harvey

[Tayana42]

Harvey, I’m sorry to hear about your fall and injury. Having been through some medical issues my self at 71 I understand. The bladder insert is a much less costly way to go and doesn’t require ripping out the interior of the boat. Mine has been working flawlessly for 16 years so far. The labor to remove the remaining fuel, grind out the baffles and install the bladder won’t be small but it should be a small fraction of the initial quote you had.

[mvweebles]

You may want to repost this on TrawlerForum.com where many of the boats have tanks of this size, and there's a decent chance you'll get another referral. I doubt a 500 gallon bladder insert is practical. Most folks replace with a series of smaller tanks. I am in the process of replacing two 200 gallon steel tanks with four 100 gallon fiberglass tanks. Cost in Mexico is around $9500.

There is no cheap solution, but some are less expensive than others.

Good luck and best of wishes for your health.

Peter.