Pinhole leak in my copper calorifier… Fix?

[Tim Good]

So my bilge alarm just went off as I was getting into bed. Did the lovely taste test and thankfully it was fresh.

Pulled up my seating and boards (whilst dressed in my pyjamas), and proceeded to find the culprit, which is a tiny pinhole in the calorifier just below the upper outlet. Since it is a copper vessel might I be able to do a plumbers weld to it somehow?

I appreciate this tank is now 27 years old and could do with replacing but I could also do with a fix to get me through this season.

Thoughts?

 

[Stemar]

You might be able solder it up, but I can't help wondering what you'll find when you start cleaning it up. It'll need to be spotless before solder will stick, and I reckon there's a fair chance there won't be a lot of metal left.

If it's domestically practicable, I'd be inclined to isolate it until you can replace it and boil a kettle when you need hot water.

 

[Tim Good]

You might be able solder it up, but I can't help wondering what you'll find when you start cleaning it up. It'll need to be spotless before solder will stick, and I reckon there's a fair chance there won't be a lot of metal left.

If it's domestically practicable, I'd be inclined to isolate it until you can replace it and boil a kettle when you need hot water.

Well you may well be right. I’m thinking about injecting some heat resistant epoxy into the hole and around the outside and see what happens.

 

[Davy_S]

I had to do a quick repair of a hot water cistern, i had this stuff handy, it worked perfectly.
https://www.amazon.co.uk/Jenolite-1...rds=marine+epoxy+putty&qid=1685005558&sr=8-36

 

[PaulRainbow]

Don't go mad with the cleaning, then this should do it:

Plastic Padding Chemical Metal 180ml | Halfords UK

 

[vyv_cox]

Soldering is perfectly possible. I would use killed spirits flux but a tinsmith I worked with years ago told me that with very dirty surfaces he would use neat hydrochloric acid

 

[Tim Good]

Just some feedback on the solution for anyone looking it up in future:

I half emptied the calorifier and added JB Weld (steel reinforced epoxy) to the area liberally. I then released the remaining half of the tank which sucked some of the JB epoxy into the hole. I then stopped draining and let it set. I finished off with a good dose of Sikaflex over the top just because I had some available. It’s been pressurised (2bar) and up to temperature for 2 days now with no leaks.

@PaulRainbow thanks for the suggestion. I tried to find Plastic Padding type you mentioned but JB weld was all I could get the day from GSF.

 

[wombat88]

CT1

CT1 - CT1

solves an awful lot of things...

 

[rogerthebodger]

Don't go mad with the cleaning, then this should do it:

Plastic Padding Chemical Metal 180ml | Halfords UK

Plastic Padding is a two-part polyester based multi purpose fix it repair paste.

Epoxy based filler would be much better IMO

Many years ago I used to use Plastic padding as a body filler on old cars and it would not stick too well to metals

 

[PaulRainbow]

Plastic Padding is a two-part polyester based multi purpose fix it repair paste.

Epoxy based filler would be much better IMO

Many years ago I used to use Plastic padding as a body filler on old cars and it would not stick too well to metals

Yet it has fixed the leak!

 

[Tranona]

Yet it has fixed the leak!

Perhaps that is because JB Weld Tim used is epoxy not polyester

 

[Clancy Moped]

27 years! You've done well.

 

[PaulRainbow]

Perhaps that is because JB Weld Tim used is epoxy not polyester

Ah yes, of course. I'm obviously an idiot who doesn't know how anything works, or how to fix anything.

I'll leave that to you experts in future.

 

[Tim Good]

Yet it has fixed the leak!

It was actually epoxy I used but over many years on this forum I’ve come to trust what Paul has to say on many heating and marine plumbing issues so I imagine the polyester would have also worked

 

[rogerthebodger]

Yet it has fixed the leak!

Did it!!! The OP poster the following

" JB Weld (steel reinforced epoxy) to the area liberally"

Beaten to it by Tranona

 

[PaulRainbow]

Did it!!! The OP poster the following

" JB Weld (steel reinforced epoxy) to the area liberally"

Beaten to it by Tranona

[Unwelcome content deleted.]

The product i suggested would have worked equally as well, i was using it in more demanding situations (not boat related) decades ago and it never failed once. It is not body filler, Plastic Padding was a trade name, not a specific material !!

 

[superheat6k]

Just some feedback on the solution for anyone looking it up in future:

I half emptied the calorifier and added JB Weld (steel reinforced epoxy) to the area liberally. I then released the remaining half of the tank which sucked some of the JB epoxy into the hole. I then stopped draining and let it set. I finished off with a good dose of Sikaflex over the top just because I had some available. It’s been pressurised (2bar) and up to temperature for 2 days now with no leaks.

@PaulRainbow thanks for the suggestion. I tried to find Plastic Padding type you mentioned but JB weld was all I could get the day from GSF.

View attachment 157333

Whilst you are basking in the success of your repair I suggest time to start searching eBay et al for the (new) replacement. When a 27 year old cylinder fails it is likely due to severe thinning of the copper and the pinhole solved is just the first. Perhaps you might get a couple of months, even a season, but I would place good money you will be replacing it soon. Don't ask me how I know this !!!

 

[Tim Good]

Whilst you are basking in the success of your repair I suggest time to start searching eBay et al for the (new) replacement. When a 27 year old cylinder fails it is likely due to severe thinning of the copper and the pinhole solved is just the first. Perhaps you might get a couple of months, even a season, but I would place good money you will be replacing it soon. Don't ask me how I know this !!!

Already on it. It won’t be from eBay that’s for sure. The effort to remove and install the tank means I’ll be getting the highest quality I possibly can in the hope it lasts another 27 years.

 

[sailaboutvic]

Already on it. It won’t be from eBay that’s for sure. The effort to remove and install the tank means I’ll be getting the highest quality I possibly can in the hope it lasts another 27 years.

Here you go ,
you just need to build a airing cupboard around it

 

[Tim Good]

Here you go ,
you just need to build a airing cupboard around it

Nope. I’m having a custom made copper one built with all the valves in exactly the same place. I’ve got a twin coil with Webasto and engine circuit and it’s right under all the cabinets. It’ll be a total arse of a job to re run everything, cutting and extending hoses.

Hoping also to add a dual 240/12v heating element. At the moment with all this sun I’ve got masses of excess solar potential with my 500w. I could be heating the calorifier if only at 300w trickle.