Annoying leak from the skin tank

[Felshampo]

Has anyone got any clever ideas how to seal a leak from my skin tank? 

I have had a leak below my skin tank for some time. I have finally found it is coming off the drain fitting at the bottom of the skin tank. This is a brass tap. It is in the bottom corner of the skin tank in a difficult to get at spot.

It is wet around the joint between the steel pipe and the brass tap. I guess it's a compression fitting. I managed to get an adjustable spanner on it and gave it a bit of a tighten. 

Ideally I should drain down the system and remove and put it back with a lot of ptfe fluid. 

Is there any other way I could seal it. I'm reluctant to put more turns on the spanner incase it breaks it and I end up with a bilge full of coolant. 

[Alan de Enfield]

 

 

Available from all good (UK) chandleries

 

 

 

Edited December 21, 2021 by Alan de Enfield

[Felshampo]

Thanks Alan

[blackrose]

3 hours ago, Felshampo said:

Has anyone got any clever ideas how to seal a leak from my skin tank? 

I have had a leak below my skin tank for some time. I have finally found it is coming off the drain fitting at the bottom of the skin tank. This is a brass tap. It is in the bottom corner of the skin tank in a difficult to get at spot.

It is wet around the joint between the steel pipe and the brass tap. I guess it's a compression fitting. I managed to get an adjustable spanner on it and gave it a bit of a tighten. 

Ideally I should drain down the system and remove and put it back with a lot of ptfe fluid. 

Is there any other way I could seal it. I'm reluctant to put more turns on the spanner incase it breaks it and I end up with a bilge full of coolant. 

 

I would use gas PTFE tape in the yellow roll rather than liquid. It's thicker than the water PTFE tape.

 

If it turns out to be a crack in the tank side of the joint then I'd drain the tank, use a gas blow torch to dry out the crack, abrade the area with sandpaper and a wire brush, dust it off and then apply some JB Weld to seal the leak. Give it a couple of days before refilling. I repaired mine this way 10 years ago and it's still fine.

 

 

Edited December 21, 2021 by blackrose

[J R ALSOP]

Milliput for me

[Ex Brummie]

Self amalgamating tape which may last as long as most other temporary repairs, and will be easier to clean off when you do the job properly.

[Felshampo]

21 minutes ago, blackrose said:

 

I would use gas PTFE tape in the yellow roll rather than liquid. It's thicker than the water PTFE tape.

 

If it turns out to be a crack in the tank side of the joint then I'd drain the tank, use a gas blow torch to dry out the crack, abrade the area with sandpaper and a wire brush, dust it off and then apply some JB Weld to seal the leak. Give it a couple of days before refilling. I repaired mine this way 10 years ago and it's still fine.

 

 

Will do if I have to empty the system... 

 

16 minutes ago, J R ALSOP said:

Milliput for me

Never heard of this but googled it and that looks just right if it's waterproof. 

 

12 minutes ago, Ex Brummie said:

Self amalgamating tape which may last as long as most other temporary repairs, and will be easier to clean off when you do the job properly.

I've got some of that, do you think it can withstand the pressure? 

[Ex Brummie]

13 hours ago, Felshampo said:

Will do if I have to empty the system... 

 

Never heard of this but googled it and that looks just right if it's waterproof. 

 

I've got some of that, do you think it can withstand the pressure? 

I've seen it used as a temp repair on a top hose on a car. 3 years later it is still intact. When you look at the specification, it withstands very high temperatures. A good few tight turns will soon prove or disprove its capabilities. If you already have some, you have nothing to lose and can do the job now. The problem you may have with the pastes is getting into the leak with any pressure to seal any cracks. 

Edited December 22, 2021 by Ex Brummie

[Felshampo]

3 hours ago, Ex Brummie said:

I've seen it used as a temp repair on a top hose on a car. 3 years later it is still intact. When you look at the specification, it withstands very high temperatures. A good few tight turns will soon prove or disprove its capabilities. If you already have some, you have nothing to lose and can do the job now. The problem you may have with the pastes is getting into the leak with any pressure to seal any cracks. 

I think it's leaking around the compression joint. Already had that with the other skin tank fitting, brass onto steel, not a good fit, don't know why they did it that way. Replaced the other one with a tail and hose with a jubilee clip, seals easily, but obviously needs the system to be emptied. This one is also in a much more awkward to get at place. I will try putting on the paste first, if that fails then I will try the tape. 

[Tony Brooks]

Is it me being thick or something odd? Seems like a compression joint onto steel pipe, that is odd, i would have expected the steel pipe to be threaded. Then a skin tank drain using a steel pipe when I would have thought a screwed plug into a boss would be simpler and more leak proof. Any chnace of a photo?

[Felshampo]

14 minutes ago, Tony Brooks said:

Is it me being thick or something odd? Seems like a compression joint onto steel pipe, that is odd, i would have expected the steel pipe to be threaded. Then a skin tank drain using a steel pipe when I would have thought a screwed plug into a boss would be simpler and more leak proof. Any chnace of a photo?

I'll try and photo it when we go back to the boat at the weekend. Th other fitting was a compression joint onto a a threaded pipe. Problem is they did not match very well. That's why I think it's the same problem. It's under the engine so difficult to get at, which is why I'm not sure exactly what it is. 

[Tony Brooks]

24 minutes ago, Felshampo said:

I'll try and photo it when we go back to the boat at the weekend. Th other fitting was a compression joint onto a a threaded pipe. Problem is they did not match very well. That's why I think it's the same problem. It's under the engine so difficult to get at, which is why I'm not sure exactly what it is. 

 

Unless it is a horizontal skin that it is even more bizarre, and if it is a horizontal tank I think it is very poor practice to put anything like that under the engine.

[ditchcrawler]

8 hours ago, Ex Brummie said:

I've seen it used as a temp repair on a top hose on a car. 3 years later it is still intact. When you look at the specification, it withstands very high temperatures. A good few tight turns will soon prove or disprove its capabilities. If you already have some, you have nothing to lose and can do the job now. The problem you may have with the pastes is getting into the leak with any pressure to seal any cracks. 

The AA man did that for me as a get you home when my top hose failed. Worked well

[bizzard]

22 hours ago, J R ALSOP said:

Milliput for me

It's very good and will cure under water. A two part epoxy putty.

[blackrose]

On 21/12/2021 at 20:10, Felshampo said:

 

I've got some of that, do you think it can withstand the pressure? 

 

It might do but self amalgamating tape is only going to be a temporary repair. Some of the other ideas will be permanent if you dry and prep the area properly. My JB weld repair has been good for 10 years.

 

On 22/12/2021 at 13:27, Felshampo said:

I think it's leaking around the compression joint. 

 

In that case forget about JB weld and Milliput. Drain the tank and remake the joint properly.

Edited December 24, 2021 by blackrose

[blackrose]

On 22/12/2021 at 16:56, Tony Brooks said:

Is it me being thick or something odd? Seems like a compression joint onto steel pipe, that is odd, i would have expected the steel pipe to be threaded. Then a skin tank drain using a steel pipe when I would have thought a screwed plug into a boss would be simpler and more leak proof. Any chnace of a photo?

 

Yes the whole thing sounds like an odd arrangement.

[Felshampo]

15 minutes ago, blackrose said:

In that case forget about JB weld and Milliput. Drain the tank and remake the joint properly.

Yeah but until I do that, as its only producing a drop or two each week, I was hoping for a temporary fix so I'll try a few of the above suggestions. 

[MtB]

"Annoying leak from the skin tank"

 

Point of Order....

 

The thread title contains a tautology. ALL leaks are annoying.

 

 

[Felshampo]

9 minutes ago, MtB said:

"Annoying leak from the skin tank"

 

Point of Order....

 

The thread title contains a tautology. ALL leaks are annoying.

 

 

Bloody right....... 

[ditchcrawler]

34 minutes ago, MtB said:

"Annoying leak from the skin tank"

 

Point of Order....

 

The thread title contains a tautology. ALL leaks are annoying.

 

 

Especially as you get older

[Felshampo]

On 22/12/2021 at 17:40, Tony Brooks said:

 

Unless it is a horizontal skin that it is even more bizarre, and if it is a horizontal tank I think it is very poor practice to put anything like that under the engine.

 

This is the best shot I could get. Hope that clears things up. 

[Tony Brooks]

OK, so a vertical skin thank and  not under the engine, but may well be a pig to get at.

 

I think that is a parallel threaded boss welded onto the tank and I bet the BSP to 15mm compression addaptor has a parallel thread on it so it relies upon a soft washer to seal against the boss. I understand from the more plumbery members that it really should have a BSP taper thread with a turn or two of PTFE tape making the seal. I doubt it is the actual compression fitting that is leaking unless  the drain cock has been stood one.

 

Nice clean bilge, I can see why it would be annoying but it looks as if it will all unscrew come the spring.

[David Mack]

On 03/01/2022 at 14:37, Felshampo said:

 

This is the best shot I could get. Hope that clears things up. 

If as Tony suggests the leak is between the steel tube and the brass adaptor I would unscrew the adaptor one full turn (it will drip a bit but ignore that), then wind in some ptfe tape twisted into a rope into the resulting groove - 2 or 3 turns - then tighten up the fitting again to compress the ptfe.

[Withywindle]

What happened in the end? Did you find a solution?

[Felshampo]

It is still an annoying leak. I have decided to put up with it until I have to inevitably drain the system and then deal with it.