Performing a fuel tank ectomy

[31seahorse]

Hello SBO Members,
To describe Friday as "Good Friday" would be a misnomer in our case. Eileen and I spent a L O N G day at the boat removing the fuel tank. We had tried all arguments possible to avoid that project, but the bottom line was: the fuel tank is leaking. I had pumped the tank empty on Monday and had stored the smelly juice in containers on deck.

The decision to remove the tank was followed by trying to figure out just how to remove it. Initially all hose connections to the fuel tank were removed, and the holding tank with its associated tubing had to be moved. (It may even find a new resting place if we decide to reposition the fuel tank.) We cut the retaining plywood to the inboard side of the fuel tank for a distance of 28 1/2 inches. Thank heaven for the Fein Multimaster tool! With a combination of prying, lifting, pushing, and gouging out styrofoam we finally moved the tank. From that point the removal of the tank was pretty easy. It actually slid out over the engine once a few protruding parts were removed from the engine and engine area. That included the battery charger, the air cleaner, a drain hose, and just moving the shift cable.

The point of my post is this: aluminum fuel tanks corrode and eventually leak. That should come as no surprise to any of us, but when it happens be prepared to work your butt off. Our tank lasted 28 years. We had nearly convinced ourselves that someone (surely not us) had accidently drilled a hole in the tank while installing some errant screw in the area. Maybe we could locate the hole and patch it. JB weld was suggested by more than one person. Our investigation started by checking all fuel lines and then opening a small inspection area in the lower, forward corner of the fuel tank retaining plywood area. At that point we found saturated plywood and oozing fuel. A repair project became a replacement project.

Finding a replacement tank has proved difficult. The original aluminum tank is a 21 gallon tank that is triangular and its bottom is slanted both to the outboard side along the side of the hull and slanted aft along the shape of the hull. I am looking at Moeller tanks of various rectangular shapes and sizes to fit onto a shelf that I will install. It seems that I will be limited to a 12, 13, or 15 gallon tank in plastic. I do not have final dimentions because I have another day of cleanup before the soaked foam will be removed.

I have attached some pictures for your enjoyment. Our boat is a 1986 Caliber 28 that we have owned since August of 2013. We enjoy the boat's sailing characteristics and are excited about getting her back into the Chesapeake Bay again by mid May.

Notice: (1) There is no room to spare. (2) It's good I'm no heavier. (3) Pitting and discoloration on the tank.

Phil

 

[Stu Jackson]

Nice job. Ain't it a PITA when the designers don't bother with little details like how to service the parts?

 

[woodster]

Hello SBO Members,
To describe Friday as "Good Friday" would be a misnomer in our case. Eileen and I spent a L O N G day at the boat removing the fuel tank. We had tried all arguments possible to avoid that project, but the bottom line was: the fuel tank is leaking. I had pumped the tank empty on Monday and had stored the smelly juice in containers on deck.

The decision to remove the tank was followed by trying to figure out just how to remove it. Initially all hose connections to the fuel tank were removed, and the holding tank with its associated tubing had to be moved. (It may even find a new resting place if we decide to reposition the fuel tank.) We cut the retaining plywood to the inboard side of the fuel tank for a distance of 28 1/2 inches. Thank heaven for the Fein Multimaster tool! With a combination of prying, lifting, pushing, and gouging out styrofoam we finally moved the tank. From that point the removal of the tank was pretty easy. It actually slid out over the engine once a few protruding parts were removed from the engine and engine area. That included the battery charger, the air cleaner, a drain hose, and just moving the shift cable.

The point of my post is this: aluminum fuel tanks corrode and eventually leak. That should come as no surprise to any of us, but when it happens be prepared to work your butt off. Our tank lasted 28 years. We had nearly convinced ourselves that someone (surely not us) had accidently drilled a hole in the tank while installing some errant screw in the area. Maybe we could locate the hole and patch it. JB weld was suggested by more than one person. Our investigation started by checking all fuel lines and then opening a small inspection area in the lower, forward corner of the fuel tank retaining plywood area. At that point we found saturated plywood and oozing fuel. A repair project became a replacement project.

Finding a replacement tank has proved difficult. The original aluminum tank is a 21 gallon tank that is triangular and its bottom is slanted both to the outboard side along the side of the hull and slanted aft along the shape of the hull. I am looking at Moeller tanks of various rectangular shapes and sizes to fit onto a shelf that I will install. It seems that I will be limited to a 12, 13, or 15 gallon tank in plastic. I do not have final dimentions because I have another day of cleanup before the soaked foam will be removed.

I have attached some pictures for your enjoyment. Our boat is a 1986 Caliber 28 that we have owned since August of 2013. We enjoy the boat's sailing characteristics and are excited about getting her back into the Chesapeake Bay again by mid May.

Notice: (1) There is no room to spare. (2) It's good I'm no heavier. (3) Pitting and discoloration on the tank.

Phil

contact best fab in fl they can make you one just like your old one ....take he tank to them and have them duplicate it exactly like the old one ...hope this helps...

regards

woody

 

[DAVA390]

two boats, twice the fun! Like I said before , you will ALWAYS have something to work on.. Good luck on this one. Dave

 

[Ralph Johnstone]

The decision to remove the tank was followed by trying to figure out just how to remove it.

Just looking at the photos, I can feel your pain.

Fortunately (I'm hoping), the tank on ours is polyethylene and will not perforate. Unfortunately, should it ever leak the only way of removing the tank is with explosives .

 

[seadaddler]

Tunnel Rat

Were you one of those tunnels rats in the war,nice going and lucky you did not
have to cut the boat up to get it out like some others have had to do.
My fuel tank is under our rear bed but plastic and my wife would be still on land if we had any kind of leak and some times she complains about the engine heat smell.
Good luck with the rest of the job and maybe you should hire out for crawling
around ours boats for those hard to get at jobs.
Nick

 

[mystery117]

I replaced the tank in my Hunter 33 last November and the removal took about an hour - one of those miraculous occurrences where Murphy had not been informed of the venture prior to it's completion. I was very thankful and ended out replacing it with a Moeller 19 gallon tank quite similar in size. I lost 2 gallons of capacity but I really don't feel like I lost anything. How often would I cruise for that long out of range of refueling w/o stopping? I'm certain 15 gallons or even 12 gallons on yours would be about the same. Think seriously about reducing capacity to enable a simplified installation. The shelf sounds like an excellent idea - no worries about matching the angle of the bottom - and the Moeller's are very affordable.

 

[31seahorse]

Were you one of those tunnels rats in the war....


Hello Seadaddler, I often think of the men who served and feel humbled. I reported as required, but knee damage put me in the "unfit" category.

Phil

 

[gettinthere]

There should be SS tank fabricators in the Chesapeake Bay area. Take the old tank to them and they will replicate it.

 

[31seahorse]

Woodster & gettinthere,

Thanks for the nudges in the direction of a new aluminum tank. Sent an email to best fab and will look for tank fabricators in the Elkton/H de Grace/Upper Eastern shore area.

 

[fabman]

Try Mattson & Co. in Tampa, Fl.

 

[bletso]

I feel for you. I had to remove ours a few years back. 100+ gal. I had to lift out the water tanks, 160 gal and set it aside, then take out the steel tank. It fit through the companion way hatch with 1/2 inch clearance, boomed it over the side and floated it to shore. I replaced it with a 50 gal aluminum.

 

[zeehag]

regarding tank removal..... the previous owners of my boat somewhere along the line removed the 120 gallons of tankage and replaced with a premade pick up truck plastic 44 gallon tank. with a bad pick up, so all the time i need to restart after 20 min of running and air lock. fun on a lee shore and rocks. loved it..now i have no more plastic pos tank..no tank at all, prior to recreation of a new one sin template. what a croc..... they SHOULD have left tank in boat, made a fiberglass tank using old tank as a core. now i get to make a new tank put of either steel or fg INSIDE boat, UNDER bulkheads, etc.
so....

do consider your replacement tank before you remove old one. mebbe it cannot be replaced so easily. just a thought.

 

[simmomo]

I am the original owner of a 1980 Hunter Cherubini. Haven't had a problem with my tank yet, but after 34 years, would expect to have sooner, rather than later. Any hints or tips for the inevitable.

 

[bobbyfingers2001]

Fabricator

Hello SBO Members,
To describe Friday as "Good Friday" would be a misnomer in our case. Eileen and I spent a L O N G day at the boat removing the fuel tank. We had tried all arguments possible to avoid that project, but the bottom line was: the fuel tank is leaking. I had pumped the tank empty on Monday and had stored the smelly juice in containers on deck.

The decision to remove the tank was followed by trying to figure out just how to remove it. Initially all hose connections to the fuel tank were removed, and the holding tank with its associated tubing had to be moved. (It may even find a new resting place if we decide to reposition the fuel tank.) We cut the retaining plywood to the inboard side of the fuel tank for a distance of 28 1/2 inches. Thank heaven for the Fein Multimaster tool! With a combination of prying, lifting, pushing, and gouging out styrofoam we finally moved the tank. From that point the removal of the tank was pretty easy. It actually slid out over the engine once a few protruding parts were removed from the engine and engine area. That included the battery charger, the air cleaner, a drain hose, and just moving the shift cable.

The point of my post is this: aluminum fuel tanks corrode and eventually leak. That should come as no surprise to any of us, but when it happens be prepared to work your butt off. Our tank lasted 28 years. We had nearly convinced ourselves that someone (surely not us) had accidently drilled a hole in the tank while installing some errant screw in the area. Maybe we could locate the hole and patch it. JB weld was suggested by more than one person. Our investigation started by checking all fuel lines and then opening a small inspection area in the lower, forward corner of the fuel tank retaining plywood area. At that point we found saturated plywood and oozing fuel. A repair project became a replacement project.

Finding a replacement tank has proved difficult. The original aluminum tank is a 21 gallon tank that is triangular and its bottom is slanted both to the outboard side along the side of the hull and slanted aft along the shape of the hull. I am looking at Moeller tanks of various rectangular shapes and sizes to fit onto a shelf that I will install. It seems that I will be limited to a 12, 13, or 15 gallon tank in plastic. I do not have final dimentions because I have another day of cleanup before the soaked foam will be removed.

I have attached some pictures for your enjoyment. Our boat is a 1986 Caliber 28 that we have owned since August of 2013. We enjoy the boat's sailing characteristics and are excited about getting her back into the Chesapeake Bay again by mid May.

Notice: (1) There is no room to spare. (2) It's good I'm no heavier. (3) Pitting and discoloration on the tank.

Phil

Please do not tell me you are trying to fit some stock tank in there or Jerry-Rig something... You can find any decent fabricator (or welding shop) no mater where you are to copy the tank exactly from the old one, you can even go for a slightly thicker gauge aluminum and the tank will fit perfectly, without any other modifications or loss of capacity, same fuel line, sending unit & vent connectors, ... You can have the outside coated with some anti-corrosive paint (or not) either way it will surely outlast the remaining life of the boat.

 

[FourPoints]

Just to add one more name to the list, RDS Manufacturing in Florida. They custom made my new 9gal tank last year off the drawings I sent them, automatically adding internal baffles that I didn't think about in the design, for about $250 incl shipping. I had nothing but good experiences with them (even though it took a week longer than initially estimated). They are USCG, NMMA and ABYC certified, and pressure test the tanks before shipping them, plus the tank ships with a WEMA sending unit already installed ($75 or so value right there)

http://www.rdsaluminum.com/

For what it's worth, it's nice having that label on the side of the tank with all the various marine approvals and certifications for the design and construction spec. Makes me sleep a little better knowing that it's not just something thrown together by a local welder and won't pop a weld when under way in rough seas.

 

[jileshinson]

Nightmare

 

[31seahorse]

Thanks for your comments, all you members,

We will be finishing the removal of the foam and some saturated plywood on Wednesday. I am considering our options at this point and have not committed us to a specific tank. (I mean my wife has not decided how we will complete this project!)

Those who have not (thankfully) had to deal with a leaking tank I salute you. What to look for you might ask...... A diesel fuel smell was for us the first sign. Second, we saw small amounts of fuel along side the engine and in places it should not have been. Using the absorbent engine diapers proved that the fuel kept coming from somewhere as we changed the pads regularly (weekly, I think). Third, we kept fooling ourselves into believing that the fuel must be coming from a hose or the water separator filter, or some yet to be discovered source. Fourth, this winter I found a puddle of fuel beside the engine after being away from the boat for two months, and the absorbent pads were soaked. Fifth, I began to see wet marks creeping up the plywood forward of the fuel tank. Finally, during our exploratory work earlier this month I cut a small piece out of the plywood at the forward, lower, inboard edge of the tank. The first cut allowed fuel to ooze out of the kerf from the blade. This is where I eventually found saturated foam under the tank. (In connection with the new installation: One company cautions against the foam cushioning for the tank and recommends strips of a material that will support the tank and avoid dissimilar metal reactions, but still allow air flow to remove moisture and prevent it from corroding the tank as quickly. I will need to review that info to find the type of material they mentioned. Any thoughts from the members???)

All the pitting on the bottom of the tank starts me thinking about the electric current issues that have been discussed here. The amount of pitting certainly did not occur in the three months we owned the boat and kept her at our present marina. On the positive side of that situation.....the marina has spent quite a few dollars on new floating docks and upgraded electric service to the docks. That should help preserve the new tank.

Thanks for your comments and interest. Phil

 

[shemandr]

Imagine if it was the holding tank!

 

[FourPoints]

In connection with the new installation: One company cautions against the foam cushioning for the tank and recommends strips of a material that will support the tank and avoid dissimilar metal reactions, but still allow air flow to remove moisture and prevent it from corroding the tank as quickly. I will need to review that info to find the type of material they mentioned. Any thoughts from the members???

That is good advice. For that very reason, when I installed my tank I had the luxury of a little space to work with, and I installed it so the tank is elevated on mounting studs about 3/4" off the hull and open all around so absolutely nothing is touching the tank (see http://sailingit.com/blog/boat-projects/fuel-system-part-3 for pictures)

Any material you place against the tank has the potential for trapping moisture and thus generating corrosion. If you cannot do what I did with mounting flanges and studs to bolt them to, I would suggest maybe having them weld some 1/2" angle material around the tank on whatever face it will be in contact with anything, to provide an offset from any surrounding material without introducing any point for moisture or corrosion. That may require a slight reduction in the capacity of the tank to allow the room for the flange, but I doubt you will notice or care, if it provides peace of mind that it won't happen again.