Crack in fuel tank

RibRoy · 10 November 2005, 10:25

I have discovered a very small crack at the top/side on my aluminium fuel(gasoline)tank.

The tank is inside the console, and the console is attached to the deck with GRP so it will be a big job to change it.

It is possible to mount a hatch where the crack is.

Is it possible to fill the tank with a non exploding gaz ( nitrogene ? ) and weld it, or is that suecide ?

On my previus boat I had the tank out of the boat, flushed it with water in 6 ours, and had it filled with water during welding, and I still had a minor explotion !!!

The boat is still under warranty, but in that case I have to ship it to the UK, and be out of buisiness for some time.

Any advice of what to do ?

Regards
Roy

Tim M · 10 November 2005, 10:37

If the boat in under warrentee, would you not be able to claim losses from the UK company u bought the boat off....

hard1 · 10 November 2005, 10:40

Quote:

Originally Posted by RibRoy

I have discovered a very small crack at the top/side on my aluminium fuel(gasoline)tank.

The tank is inside the console, and the console is attached to the deck with GRP so it will be a big job to change it.

It is possible to mount a hatch where the crack is.

Is it possible to fill the tank with a non exploding gaz ( nitrogene ? ) and weld it, or is that suecide ?

On my previus boat I had the tank out of the boat, flushed it with water in 6 ours, and had it filled with water during welding, and I still had a minor explotion !!!

The boat is still under warranty, but in that case I have to ship it to the UK, and be out of buisiness for some time.

Any advice of what to do ?

Regards
Roy

Surely epoxy and/or glass cloth would seal such a crack? Sikaflex also perhaps?

jwalker · 10 November 2005, 10:44

If using the water wash in future, you need to use a detergent in the water to emulsify the remains of the fuel. I've also found powder for domestic dishwashers to be excellent. The water should be hot when flushing.

However, if you do not want to involve yourself in the hassle of a proper repair, there are products for repairing leaks in petrol tanks. The one I have used, and it worked very well, is marketed in the UK as Petropatch. You may well have something similar in Norway. I have also used the epoxy putty type but after a time it came away.

A couple of points: It is difficult to get adhesion to aluminium.
If the tank has cracked in use, that area must be flexing and a repair may only be temporary.

Scary Des · 10 November 2005, 10:48

In simple terms, Aluminium worked hardens over time and on an area that is flexing a lot this will happen quicker

Equally areas close to welds or bends where the condition of the metal has been changed by heat or movement will also be harder and more prone to cracking

so if there is one crack there is probably be more

Welding tanks is very difficult and I wouldn’t want to do it still fitted in the boat

Des

jwalker · 10 November 2005, 11:30

Quote:

Originally Posted by Scary Des

In simple terms, Aluminium worked hardens over time and on an area that is flexing a lot this will happen quicker ..

Being a bit pedantic....pure aluminium hardly work hardens at all. Many of the alloys age harden substantially and then flexing takes it's toll.

Just a thought for you, Ribroy; you can anneal the aluminium alloy by applying heat. Unfortunately there is no colour change as there is when heating steel but, very fortunately, soap turns black at just the right temperature. Rub a bar of soap onto the surface at the crack and then heat it until the soap turns black. Do not continue heating it or it will turn into a gloop and collapse. Aluminium has a very short pasty stage. You'll need to flush the tank first though.

Scary Des · 10 November 2005, 11:47

Quote:

Originally Posted by jwalker

Being a bit pedantic....pure aluminium hardly work hardens at all..........

No you be pedantic

you are right about pure aluminium

but the marine grade aluminium tends to have a bit of magnesium added to make it a bit harder and more corrosion resistant and therefore prone to cracking

I’m not sure that people working in the marine trade always apply sufficient thought to the use of the correct grade of material. For example you see carbon fibre used where it can have no benefit

but hay, it looks good

Des

Jono · 10 November 2005, 12:32

Quote:

Originally Posted by Tim M

If the boat in under warrentee, would you not be able to claim losses from the UK company u bought the boat off....

Go on..... You're havin' a laff aren't you? Consequential losses aren't typically covered by any warranty.

Tim M · 10 November 2005, 12:37

We're doing business law at the moment and some case we read came to mind. I am just lowly first year so I am probably wrong.....

Simon B · 10 November 2005, 12:38

You could stabilise the crack by drilling a hole at the end of it to prevent progation, the various good patching methods thus described will not be able to do this.

Aluminium can be bonded chemically in a number of circumstances aircraft are bonded. Welding aluminium is skilled and welding a tank that once contained fuel should be done after it has been steamed out for some time. More than likely the welder would also sparge the tank with the shielding gas in use so helium mix/pure or Argon mix/pure (I think?)

Bottom line is a new tank on new boat shouldnt crack it is getting stressed from somewhere. Annealing might help but could cause expansion problems. Welding does have the effect of annealing locally but either side the weld a heat affected zone is formed. This is where a failure could occurr if there is one.

codprawn · 10 November 2005, 12:56

You could always braze it using lumiweld or similar - use the soap trick and make sure you purge the tank VERY well - hot water and washing up liquid as someone else said.

I used a very botch job on an aluminium fuel tank once - sandpapered around the crack and used some solvent/thinners to remove any grease - then used plastic padding elastic car body filler - it was a central heating kerosene tank and it is still fine 15 yrs later!!! Doesn't look too pretty though!!!

Pete7 · 10 November 2005, 13:06

Ribroy, if this boat is your business then do it properly. Rip the damed thing out of the boat and chuck it in a skip, then get a proper fuel tank fitted. If its cracked once, there is a problem and patching or welding isn't going to solve it, only mask it. I wouldn't have thought more than 2 weeks work to change and then you will know that the boat is safe. Petrol leaks on a charter boat, hmm nice

It must be getting kinda cold up there now, can you not find a two week window in the charter season to carry out the work ? If you want I will come and do it for you, getting quite good at changing consoles

Pete

Searider · 10 November 2005, 14:58

Quote:

Originally Posted by RibRoy

The boat is still under warranty, but in that case I have to ship it to the UK, and be out of buisiness for some time.

Any advice of what to do ?

Regards
Roy

I would suggest that you get in touch with the builders as soon as possible.

They may be able to offer a solution - or may even appoint local contractors to carry out repairs / replace tank on their behalf.

Tornados have a good reputation and I would have thought that the builder would stand by their product.

Probably best to talk with them rather than us!

RibRoy · 10 November 2005, 16:02

I think I go for Pete7's suggestion. I have already patched it with Plastick Padding, and as long as I dont top the tank it is no prob at all. The leak is so small that it has to be cold to locate it. If above 10 c it vaporises, before you can spot it.
I have no booking in Jan, so I put in a new tank then.

Thanks to all for your help

Ragards Roy

RibRoy · 10 November 2005, 16:06

Quote:

Originally Posted by Searider

I would suggest that you get in touch with the builders as soon as possible.

They may be able to offer a solution - or may even appoint local contractors to carry out repairs / replace tank on their behalf.

Tornados have a good reputation and I would have thought that the builder would stand by their product.

Probably best to talk with them rather than us!

Tornado wanted the boat sent to UK, but I have just talked to the Norwegian distr. and he belive they agree that it is fixed here i N.

Where i N is the new home of your boat ?

Reg.
Roy

Rene · 14 November 2005, 10:58

Hi Roy

This is not the first issue with a cracking tank in a charter Tornado this year.

There is one here in Denmark too, but this crack was on the underside of the tank, and therefore had to be fixed at once.

I really don't think the boat went back to the UK, but I'm not sure.

Talk to Tornado, I think they would be keen on fixing this fast

Regards
Rene

Fjordrafting · 16 November 2005, 22:04

I do not understant why a high quality boat like Torado still has the tank inside the console, on the deck. As far as I know, the tanks do not crack when not moving.
So, Dear Tornado, you do have a very good reputation in both Norway and Sweeden do not spoil it with tanks inside the console.
I have heared that Tornado are making an 11m rib where you can have the tank under the deck, if you are willing to pay, that is. This tank is made from the glassfiberconstruction already there, meaning they do not put any metal-tank there. Is this right, and does it work well?

Searider · 16 November 2005, 22:25

Quote:

Originally Posted by RibRoy

Tornado wanted the boat sent to UK, but I have just talked to the Norwegian distr. and he belive they agree that it is fixed here i N.

Where i N is the new home of your boat ?

Reg.
Roy

Hi Roy,

I'm glad the builder has agreed to sort out your problems. I have just spent three days in court giving evidence against a difficult builder and neither the boat owner or the builder would say that it is a pleasant process.

Not sure where in Norway my Searider is. JBT sold the boat for me and they told me it was going to Norway.

Keep an eye out for it - it would be good to know it's gone to a good home.

RibRoy · 17 November 2005, 17:40

Hi !

Not shure what will happend with the tank, still waiting an answer from the N dealer.

The crack is not from moving I think. Its a small dent i the middle of the plate 5 cm from the top, must have been some sort of external contact before the console was fitted ?

Reg.

Roy

gavin · 18 November 2005, 17:48

Pity about this, what a nuisance, Tornado has a good name, at least its above deck, even though its hard to get at