Soldering a Calorifier?

[Anthony]

Hi,

I have a copper calorifer that has a very small leak, its in the form of a few mm long 'scratch' where it looks like it was maybe caught in the machine when being rolled there to make the join, and that scratch has developed a pin prick hole.

Anyway I am convinced that it could be soldered up, but am I right in thinking that it would need to be silver soldered, not just normal soft (electrical) solder?

Or is it worth trying to soft solder it? (I am cruising in med and dont have silver solder on board, or a way to get it hot enough, where as I could prob soft solder it).

Any experience appreciated!

Ants

 

[Talbot]

Rather than soft solder, I think I would empty the calorifier and try to squash some araldite into the hole. - if you use rapid, you will soon know if successful!

 

[savageseadog]

Silver Solder is stronger, is there any pressure ? If not I would suggest soft solder tin/lead ie normal stuff. Use a copper patch over the hole you could make a patch by slitting a small piece of tubing and flattening it, overlap the repair by 10-15mm . Due to possible corrossion I suggest cleaning with fairly coarse emery/wet and dry paper and use hydrochloric acid on the actual crack, hydrochloric acid can be obtained as brick and concrete cleaner. Make sure you use a decent flux and ensure the area is dry. Also ensure that the tank is disconnected in some way as pressure could build up and the repair would just blow through you would use a small gas blowlamp for this perhaps benefit from a butane/propane mix for quicker heat than just butane. If you wanted to silver solder you could possibly do without the patch, you can use borax as a flux from a chemist. you would probably need a small oxy butane/propane set for this . Also watch you don't melt adjacent seams. This can sometimes be handled using wet clay or water

 

[savageseadog]

As a follow up to what I just said, use normal tin/lead solder as I've had poor results with lead free solder. I don't know what anyone else thinks ?

 

[LeytonC]

Yes, lead free solder is no good at all, you need stuff with lead in it.

 

[BlueChip]

What about a patch stuck on using sikaflex?
Would be a lot easier than soldering

 

[Strathglass]

Yes, Been there, done it.

On a hire fleet a few years ago. On the Caledonian Canal.

The calorifiers had not been emptied at the end of the season before the heavy frost came.

Took out six of them.

Four were repairable, without patches.

<font color="red"> Do NOT use solder but braze them </font> as has been sugested by a previous poster.

They do become presurised and I do not think solder would be strong enough.

Three of the repaired ones were refitted and worked as good as new for many years.

The fourth one is on my own yacht.


Iain

 

[cliff]

Go ahead with ordinary leaded solder. How do you think it was made originally? Brazed? Silver Soldered?, how do you think car radiators are made? - yep you got it solder, plain old ordinary solder - nothing fancy needed - why make life difficult for yourself. Make sure the area is clean - a bit of wet and dry or the like or even ordinary sand paper. Tin (apply solder to) the surface all round the pin hole making sure there is full coverage then apply a small blob where the hole was. Do use a good flux such as Bakers soldering fluid #3 or Fry's soldering flux. If you have good quality cored solder that should workjust as well.

The best results will be obtained from using a soldering bolt rather than by directly heating the calorifier material with a gas torch (unless you are quite skilled and have a small flame on the lamp). If you want you can add a patch using an old tin can - I mean a real tin or tin plated can. Cut a small patch from it and pre tin one side before applying over the repair area. I keep an old copper soldering bolt on board for most soldering work - it can be easily heated either with a blow lamp or on the cooker.
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“Artificial intelligence is no match for natural stupidity”
Skype id:cliffillupo

 

[robind]

I did a similar repair to a calorifier on one of my boats, a few years ago. the split followed the line where the end cap had been spun to shape, in manufacturer. it was worse than I first thought and extended some two inches further that initially seen. I cut a patch from and old household calorifier obtained from the dump. and beat and cut it to cover the split by a half inch all round. The fit was important so I used a piece of soft wood and a ball pein hammer to beat the best fit possible. I then tinned the calorifier having cleaned the area of the split suitably. I floated some lead solder onto the patch (ie wiped it on with a fluxed piece of corrugated cardboard, in the absence of a moleskin wiping cloth) I then brought the two items together and heated them until they soldered. The repair was great and stayed good for a number of years however the same situation occured opposite on the end cap and so I changed the calorifier. I do believe that repairing these can only ever be looked at as a short term cure (was in my case) so "pay up and look good" and buy a new one. There is a guy in the Isle of wight does them exceedingly economically. he is at the beauleigh boat jumble usually and would highly reccomenr him to anybody. Name!!!!! I can`t remember! but I am sure other forumites will know!
Rob

 

[nedmin]

As an Armature Winder,many years ago!! solder it, you will get on better if you can get some solder with a higher lead content than the type used by electronic engineers,plumbers cored solder ( not plumbers metal) should be OK. If you could get hold of a large copper soldering iron that you have to heat on a gas ring that would be better. the problem is the copper calorifier will need a lot of heat.so you will need a large electric iron.If I was doing it I would wipe a joint,get some plumbers metal ,gas blowlamp,piece of emery cloth,flux, Clean well apply flux,then heat holding the stick of plumbers metal onto the fault ,move it round and "tin" the area,when done turn the emery cloth,cloth side you need,, cover with flux,and use as a wiping cloth.If you are careful you can turn the solder into a jelly like substance and smooth it over the hole.If you get it too hot it will all drop off!!