Trying to fix a leaking copper hot water cylinder

Changed the immersion heating element on our hot water cylinder and found it had a small leak on the edge of the screw thread insert where it joins to the top of the copper cylinder.
Trying to fix it by filling the gap with solder.
Cant get a replacement for at least five days due to national holidays so hope this works!

[@dans9953]

Great job!:). Our is leaking somewhere under the flange. I thought it was a puncture in the copper immersion pipe so changed immersion but still leaking. New ones are crazy expensive, but considering changing to another copper one I was looking also at the steel ones. Before I will do it I want to fix it quickly like you did. Would really appreciate if you could tell me what I need to buy:)?:
- lead solder
- plumbing flux
- gas torch
...
Much appreciated!

[@BrianDorey]

You need plumbing solder, plumbing flux and a small gas torch.
You need to clean the area to remove all traces of insulation and if you use some very fine sandpaper to score the surface it will help the solder to stick better.
You also need to stop the heat from the flame touching the remaining insulation so a flatten tin can or other metal shield will stop the insulation from getting too hot.

[@dans9953]

@@BrianDoreyThank you👍. Much appreciated.

[@conaran7039]

Did it work?

[@BrianDorey]

Yes, it hasnt leaked yet!

[@conaran7039]

Great job. Just normal solder and flux? New cylinders are very expensive these days.

[@BrianDorey]

@@conaran7039 I used lead solder and plumbing flux to fix it.