Fuel and Water Tanks Removal

[jaunty61]

Hello, ..I'm new to the forum and hope to find advice on tank removal/replacement.  I have a 1986 LM 28 with now, two failed tanks.
The water tank failed 2yrs ago, temporarily repaired with epoxy and recently (August 2016) the fuel tank began leaking.  The original SS fuel tank has many black, carbon specks on exterior, I suspect from moisture.  I can not see from where it's leaking and believe one or more of these carbon specks "pin-holed" the tank.
From inside the starboard cockpit locker, below the shelf boards, I have access to the rear of the tank and the tabs for securing it.  It's the forward end that I can not see where it's secured.  It appears ( and I'm afraid to think true), that the tanks were installed before the interior GRP layer that makes up the floor of the Pilothouse.  
I would greatly appreciate some guidance from someone experienced in removing these tanks before I begin cutting into the Pilothouse.
Thank you
John T

[nauticalnick]

Hi John,

That all sounds a bit drastic but before you start cutting etc have you checked all the hose connections - filling, breather etc ? These can be annoying source of leaks and can be a real pain to trace !

l'm surprised at the s/s fuel tank developing a leak and the black specs could just be mould. l have not removed the tanks on my LM30 but the construction sounds very similar and the inner mouldings that support the joinery all appear to be bolted to the wheelhouse and deck mouldings. l would be inclined to remove as much of the woodwork etc from the wheelhouse as possible to see where the tanks are attached and if they can be removed without major surgery.

Certainly the tanks etc would have been installed, as would the woodwork prior to the deck and wheelhouse mouldings being fitted which of course makes it more complicated to replace such items years later.

Hopefully another member may come along with more detailed guidance.

Regards,

Nick

[jaunty61]

Hi Nick, ...thanks for responding. Eleven gallons leaked out, thru the closet, across the floorboards and soaked the carpet, all of which also needs replaced.
I am certain that the tank leaked either at a welded seam or pinhole from the carbon specks on tank. Picking at the black specks reveals the deterioration of the SS.
I do agree that wheelhouse woodwork is the place to begin.

[Charles]

John, have you considered lining rather than replacing your existing tanks? Our original water tank is still in situ but it has a flexible liner which was inserted through a surprisingly small hole in the top of the glass fibre tank. We replaced it a couple of years ago with no difficulty. I know that both Vetus and Plastimo make these flexible water tanks and I would expect that they, or others, also make flexible fuel tanks. Worth trying.

Good luck

Charles

[nauticalnick]

Hi John,

That sounds like a serious issue with the fuel tank. Therefore l think Charles has come up with a very good suggestion and certainly if l were in your position l would going down that road.

Regards,

Nick

[tonyp]

Would definitely support Charles' suggestion first. Duratank.com might be worth looking at and talking to. Our cracked water tank is going to be sorted this winter the same way as Charles' was.
Good luck

Tony

[jaunty61]

Thanks for the replies and suggestions. I am investigating so called 'bladder tanks'. There are some good companies offering custom sizes. One challenge is to remove all the baffling inside and smooth all surfaces. I believe this is possible by cutting out the accessible aft end of the tank, cut out baffles , install bladder, and replace aft end of tank with a plate or cover of sorts. Second challenge will be aligning all of the connected plumbing.
I am hoping to hear from someone who has done any sort of repair to the fuel tank. I will keep this forum updated as to how I eventually have it repaired.

[johnty]

Hi Jaunty
I'm catching up on this rather late in the day but wonder how you got on with your fuel tank replacement as I'm having similar issues.
Thanks.
Johnty

[ro53]

Sept 4, 2016 11:26:55 GMT Charles said:

John, have you considered lining rather than replacing your existing tanks? Our original water tank is still in situ but it has a flexible liner which was inserted through a surprisingly small hole in the top of the glass fibre tank. We replaced it a couple of years ago with no difficulty. I know that both Vetus and Plastimo make these flexible water tanks and I would expect that they, or others, also make flexible fuel tanks. Worth trying.

Good luck

Charles

Hi Charles. I have an LM27 like yours. And I have to put a flexible liner in original water tank. Can you tell me what flexible liner did you put?, and what dimensions did it have?. I have seing Plastimo and Duratank, but I don't know which is better neither dimensions of original tank.

1.- Duratank:
www.duratank.com/tanks-and-liners
Duratank flexible liner dimensions.pdf (126.08 KB)

2.- Plastimo:
www.francobordo.com/deposito-agua-potable-flexible-150-litros-plastimo-p-1460.html

Thank you in advance.

Juan.

[Charles]

I think it was a Vetus, but I'm not completely sure; it might have been a Plastimo. Away from home - actually on board - so I can't check.

[ro53]

Jun 18, 2018 19:23:20 GMT Charles said:

I think it was a Vetus, but I'm not completely sure; it might have been a Plastimo. Away from home - actually on board - so I can't check.

Ok. Thank you very much, Charles.