petrol tank leak

[neilstock]

Hi I have a 26' Cruisers International with a 120 gallon aluminium petrol tank that has developed a small leak, we believe it is caused by corrosion or a cracked weld on the bottom of the tank.

Due to its size the tank cannot be removed without causing massive destruction to the boat so I was wondering whether anyone knows of anyone selling liners or sealants that might be up to the job.

I am more than happy to pay for a professional to come do the work as frankly I am only too well aware of the risks of petrol vapour, etc! but I have been unable to locate anyone.

THe boat is in Essex

 

[carlton]

Hi Neil,

Welcome to the forum.

What a grim start! I hope I'm wrong, but I'm not aware of any company that can repair a duff tank from the outside whilst it's still in the boat.

You may be best advised to bite that bullet and get a g.r.p. specialist in to advise/quote for removing/rebuilding chunks of your boat in order to replace the tank. Painful I know, but at least it's the right time of the year to get a big job like this out of the way.

It's your call, but if it was me I'd stick a new tank in there rather than trying to fix the leaky bit. If you have one weld which has cracked, how far behind it will any of the other welds be?

Good luck with it, either way.

 

[DAKA]

You cant put an inner in as your tank will have baffles in it ( dams to stop the petrol sloshing around too much)

If you can get to it you need to put a small amount of Blue Hylomar gasket sealant on the crack, this is resistant to petrol and never sets, then put Aluminium cold weld over it that sets hard to protect the Blue Hylomar.
http://www.hylomar.co.uk/
But the tank will be under your rear bed and you most likely need to remove the base of your bed with a circular saw set at ½ inch.
Cut the base out and lever it out.
Your tank will then be visible but glassed in so you need to cut around that.
There will be straps under the tank from when the manufacturers lowered it in place, use theses straps to remove your tank a few millimetres at a time.
Replacing is not that easy as the hole it sits in will be tight, have the new one made a little smaller, screw the floor back down and fill the saw grover with epoxy filler, white 2 inch carpet tape gives a good finish under your bed mattress.

Its not repairable, some will wash it out and try to weld it full of water but the type of clown who will risk a bodge repair is also almost certainly the type of clown who will cock up the welding mix, leave soot in the weld leaving another leak.
I have removed and replaced about 4 tanks, lot of hard work, working in cramped positions, depending on your bed head room you could have a big thin tank made to sit on your bed, then put a new floor on top with a thin mattress.

Unless you can see the leak with out removing it you have a lot of work and expense unfortunately.
If you have a new one made it is preferable to find a specialist, 3 out of 4 tanks made for me leaked worse than the one I was replicating, eventually the manufacturer then had one flown from America by the original tank manufacturer as the local self claim experts couldnt manage the weld air/oxygen mix.

 

[coliholic]

Well Dacarak's summed up the job pretty well for you - it's a nightmare. But you don't have too many choices if you're sure, absolutely 100% sure, the the leak is in the tank and not the surrounding plumbing. Are you really really really sure it is the tank leaking?

As far as I can see, if it is the tank, you're got two choices. One as the others have said is to replace the tank and that's by far and away the best choice.

One other option is to reseal it using a proper fuel tank sealant. Aircraft fuel tanks are made of aluminium and they regularly develop leaks and there's a proper approved way to fix them. There's a range of proprietory sealants used in the aircraft industry and if it were me I'd take myself down to a local airfield, have a chat with one of the Mechanics working on small stuff like Cessna's or Pipers and ask what they use and can you buy some off them? PR7 comes to mind but I'm not 100% sure if that's what it's called. Of course you could always offer plane fixing bloke 20 quid to come and do the job for you. Personally I'd sweeten the offer with a "bring your wife or girlfriend and we can go out in the boat and have a play and here's somne dosh for your time".

Whatever you decide to do, please don't even think about welding the tank in-situ. It would have to be removed from the boat, steam and pressure cleaned to ensure there's not the slightest trace of fuel in or around it before even thinking about getting a TIG set out. IMHO you'd be crazy to think of welding it, but then I think you already know that, don't you?

 

[neilstock]

Thanks for the replies. I cannot be certain that it is the tank that is leaking - it could of course be the fuel pipes but everything is buried and encased in expanded foam. The leak itself is very slow but of course there is no such thing as a "small" leak - especially when it comes to petrol!

It dawns on me that although the tank is 120 gallons that is a US measure and hence only 100 UK gallons - which makes the task a tiny bit more manageable (I'm trying to convince myself!)

I am obtaining a quote to convert to LPG as this could kill two birds with the one stone.

 

[Davy_S]

Its a while since I was last in the UK, there used to be a product called(petrol patch: from what I remember it used to be a jar of gunge, and a patch about 2 inches square. The little jar was like nail varnish with a little brush in the lid, you cleaned the area, painted the stuff on, then put the patch on and painted over it, it set very quickly, and worked.
I have no Idea if it is still sold, maybe someone else remembers it?

 

[carlton]

...I am obtaining a quote to convert to LPG as this could kill two birds with the one stone.

Or seriously restrict the numbers of potential buyers when the day comes around when you wish to sell the boat.

Can you fill up with lpg in your part of the world, as access to lpg seems a bit hit and miss generally?

 

[neilstock]

Actually LPG is more readily available than petrol. Constant trips to the pontoon with jerry cans is no fun!

 

[carlton]

Then that could well be the answer!

 

[enterprise]

Tank RE-Nu

Been there & have the Blood stained T shirt to prove it, not the easiest of jobs (infact the hardest).
Sorry but theres no quick solution.

Things you need to consider;

You have to drain the tank, no pella extractor etc is rated for removal of petrol, infact it has warnings against it, you cannot syphon it out (unless the tank is higher than the recieving tank).
You cannot start your engine's (vapour) or run anything electrical, so no drills or saws etc(even lighting).

Best option is to have it towed to the nearest liftout & have it lifted, syphon the fuel out once on dry land.

If you can get at the tank & remove it in one then these guys, see link (or other franchise) can salvage your existing tank.
Couriers collect & return it so no messing about on your part, it's the easiest sollution if you can remove the tank in one (& by far the cheapest).

Dont envy you the task ahead.

http://www.fuel-tank-renu.co.uk/pages/tanks.html

 

[Peanuts]

From your post do I assume you have actually found the leak?
As already mentioned the aircraft industry use a sealer for the fuel tanks, it can be used on the inside or outside of the tank. I repaired my aluminium fuel tank on my Sunseeker that was surrounded by polyfoam that had trapped the moisture and corroded away in places. I removed the foam, cleaned the surface and spread the sealer over the area concerned - result no more leaks. I am not saying this would sort your problem as I do not know your exact reason for the leak but it could help. The sealer comes in different drying times, 30 minutes and 2 hours although you leave it for 24 hours and with these timings you can have brushing and spreading type. The name of this sealer that PR1422 and is manufactured by PRC-DeSoto International.
I hope this is of some help to you.

 

[neilstock]

Thanks for everyone's help on this issue - I've joined other forums in the past and been treated like a right idiot but I am impressed by the onstructive and helpful suggestions so thanks.

I had assumed that my tank was very deep but having just calulated the approximate volume (as I can now see the length and width) the depth can only be about six inches so I am confident now that I will be able to remove the tank without too much devastation.

Depending on what I find I may well attempt to seal it with PR1422 aerospace sealant but frankly I will be quite happy to pay someone to fabricate a brand new tank if that is what it takes.

So thanks everyone - I now have a job to do!!

 

[oldgit]

Problem going back to 1980s.Do we never learn?

Common design fault.
A good chance that the bottom of the tank was installed directly on the hull possibly in contact with some material able to retain moisture(Chipboard/particle board/felt padding etc ).
When the tank on my very early Regal had to be removed due to leaks,the entire bottom plate of the tank was peppered with small corrosion spots ranging from mild discolouration to actual pin holes.
A complete new bottom to the tank was the fastest/cheapest method of repair.
Just getting the tank out was the main problem,convinced that the petrol tank was suspended in the factory on bit of wire and the rest of the boat assembled round it in order to make repairs as difficult as possible.

 

[coliholic]

Thanks for everyone's help on this issue - I've joined other forums in the past and been treated like a right idiot but I am impressed by the onstructive and helpful suggestions so thanks.

!!

Oh we can do that too if you like, though you're better off in the Lounge if you want abuse.

 

[Pennpromo]

Fuel Tanks

Hi Neil,
A blatant plug here for my company: The Tank Company in Poole, (01202 682830).
We never ever repair. As many have said you will regret it. There's no way of welding in the boat, so the tank has to come out. When you weigh up all of those costs its a false economy I am afraid.
As others have said its probably a corrosion issue under the tank. It may well be bedded down on rubber tape, this holds salt water, over the years it eats into the bottom of the tank very slowly.
We have twenty or so year old tanks that we made for Sunseeker that we are now replacing with exactly that problem.
As a really rough guide a fairy "boxy" tank of about 250 litres would be in the region of £400 or so plus VAT in powder coated aluminium.
We can arrange collection of your old tank to copy etc etc.
If you have a sketch of what you need I can give you a firm price.
SIMON

 

[regal 24.5]

I,ve this same problem with my 24.5xl regal
When i bought the boat it was fitted with a v8 gmc diesel (real bad job) with the tank 3/4 filled.
Refitted with a volvo drained the tank and filled it with 50 ltrs petrol to find it in the bilge next day.
So this big job for the winter