Diesel fuel filling pipe

[Moodymike]

Overfilled my diesel tank to-day (B32), found that where the pipe joined the tank there was a leak either due to clamp not tight enough or poor fitting, about a litre ran down beside the tank into the bilge. I do not think that the pipe quality is as good as the rest of the boat, has anyone had similar problems?

[Kerry1]

Are you sure it was the pipe fitting or did the overfilling cause fuel to overflow through an internal vent? Not sure of the setup but often these tanks have a smaller gauge pipe as breather following main fill pipe to deck fitting which sometimes stops just short of deck. When the tank fills right to the top they can overflow inside the hull.

[Moodymike]

Thanks for your suggestion.   I am convinced that the leak was through where the main pipe joins the tank . The pipe seemed very brittle and the clip could take a few turns.

[CRYSTAL]

Mike

If not too late,  what was it at the end? Cracked pipe or the tail pipe fitting / connection at the tank? That fitting can easily be  loosened.

Regards

[Moodymike]

After the fuel level fell had no more leaks including sailing well heeled. Still think main pipe is suspect it took  a few turns on the clip. Will think about replacing pipes next season  providing original pipes come undone.

[MarkTheBike]

MoodyMike

Is your filler on the transom and is there a small fitting nearby with a covered hole in it? If so then that should be the vent. It's definitely how it is on our B34. I don't think boats are allowed to have diesel tank vents inside the hull, are they? My first thought would be a loose jubilee clip and then check for rotted pipe (although it shouldn't be as it's out of the sunlight).

[Moodymike]

The vent pipe is attached to the filler cap assembly as part of one unit and vents through the cap.

[MarkTheBike]

Ah, so more like a car set-up. Well, I can sort of understand the reasoning behind that - it's probably much neater - but I think I prefer a separate breather hole. You can hear the air whistling up it as the tank gets near to full. It does sound like your loose fitting may have played a part, fingers crossed that you've sorted it.

[Moodymike]

Just filled the tank and the leak is still present . Removed the hose and discovered attached pics. My assumption is that it occurred during assembly. Any ideas on how to tackle this problem?

[patprice]

Can not quite see in the photo...but how is the spigot joined into the tank ?

[Yngmar]

It'll be plastic-welded to the rest of the tank and therefore is made from the same HDPE. Here's what I would do:

With the tank near empty (safety precaution), you should be able to bend it back into shape by careful application of a heat gun. It will however not be strong enough, so measure the inner diameter and get someone to turn you a piece of stainless tube to stabilize the inside against the clamps. Then degrease, apply some thickened epoxy and wait for it to cure completely before clamping the hose back on.

The tricky bit will be doing this without dropping anything down the tank

[Nigel]

Yngmar beat me to it, but perhaps plastic pipe would be OK?

[Salty]

...........With the tank near empty (safety precaution), you should be able to bend it back into shape by careful application of a heat gun...........

I would be extremely cautious about the use of heat where that came from the use of any unguarded flame or from any other incandescent heat source or electrically heated devices.
Although diesel oil does not normally catch fire as easily as other more aromatic fuels, it is possible, even if somewhat unlikely, for it to contain traces of those other fuels which could trigger a fire when in the presence of a source of ignition. This will depend on how strictly you or anyone else using your boat have been about ensuring that the fuel in your tank has not become contaminated either by you or your suppliers. An example of such contamination might be the use at some time in the past of an apparently empty petrol can that has been brought in to use to carry a quantity of diesel fuel to your boat where that can has been used because you don't have a diesel specific fuel can for such purposes. Just the vapour within a petrol can may be sufficient to affect the flammability of any diesel oil carried.
On a separate point, if your actions did result in a fire on your boat, firstly you would have a slightly complicated route to follow to get away from the fire such that it could be a danger to you, secondly if you were in a marina with other boats nearby, any fire on your boat could spread to those neighbouring boats, and thirdly where would responsibility lay if other boats, marina facilities or other people got burnt, and I would not rely upon having an insurance policy to cover for such incident.
If your boat is located within a marina at the time you propose to carry out such repair, it could be worthwhile discussing the problem and intended repair procedures with your marina manager.
An alternative to using a heat gun might be to build a moat around the filler pipe, and having first emptied the tank, then fill the moat with boiling water while using some kind of tool to gently stretch the neck of the filler pipe back into shape. Obviously you would need to take precautions to prevent water from entering the tank, or take appropriate action to remove any that did get inside. Lastly to retain the shape of the filler pipe you might be able to get a "pipe insert" from your local builders merchant which could be put in place before refitting the filler hose. Good luck.

[Ziffius]

Is the boat oldish or new enough that you might have recourse to the supplier as it looks likes manufacturing defect or grossly negligent installation?

[Moodymike]

The boat is a B32 2003, strange thing is it has gone 11 years without a problem.

[Kibo]

To avoid the heat issues already stated how about putting a thin stainless annular ring outside the fitting over the top of the bent part, fill the gap below the kink with amalgamating tape and then pour-fill the outside of kinked part with silica thickened epoxy. That should eliminate the leak coming through the outside of the pipe through the kink. I have no real life experience of the issue but something like that is what I would do.....

[Nigel]

Personally I think the "problems" concerning heat are over-cautious. I would stuff a rag in the top, and heat from below.

[Moodymike]

Have solved the problem with a similar method to that which Kibo describes above. Thanks for all the other suggestions.