Unsoldering joints

[Chris]

I have a problem unsoldering a joint in the airing cupboard which is connected to the main feed from the tank to the pump in the radiator system.

It is a 22mm pipe and I have held the blow torch in it for at least 25 minutes but the joint will still not release itself.

I know that there is no water in the pipe as I have drained the system. I have another joint from the rising main with which I had a similar problem and even with it removed and in the garage and in a vice I still could not release the joint.

Can you advise me on how to remove the joint without cutting the pipe as this would cause even more problems.

[Alex]

Pipe grips on the fitting then apply blow lamp and twist grips up and down with a slight sliding action,works for me

[Chris Oates]

Try to flow some new solder into the joint - same thing happens with printed circuit boards.

C

[BigWallop]

If the pipe is still connected at the other ends, then you won't be able to twist them to get the fitting off, which is the easiest way.

Holding the flame on the fitting for that length of time will also cook the fitting and make it even more difficult to remove.

The best way is to take the fitting in a pair of pliers and then heat it while trying to twist it with the pliers. You should feel it release its grip around the pipes. Keep the flame moving all round the fitting while doing this. Once it has released, remove the heat and keep twisting the fitting, and maybe spray some water on it, until it cools and the solder has solidified but not had a chance to grip on the pipe again because of the twisting movement. Don't stop twisting it, is the key.

[PoP]

Others have made valuable suggestions which should do the business.

However don't sacrifice the idea of cutting the pipe above and below this fitting - it's easy enough to insert a new length to replace what you take out, and if you used compression fittings for this then you won't have to mess with solder joints again.

If you haven't got room to use a large cutter in the space available then try a pipe slice which only needs minimal room around the pipe, and leaves the end of the pipe almost ready for putting into a fitting

- possibly will need slight deburring, and cleaning if you go for solder again.

PoP

[tarquinlinbin]

If youve had a blowlamp on the joint for that length of time and it has gone through every colour of the spectrum then it may be a lost cause. Once this happens you have almost "welded" the joint together and worse still,you have annealed the copper thus making it softer and less able to take the application of tools. The chances are that you are going to have to hacksaw it at this stage..

joe

[Alan James]

More, different but maybe easier to solve. All problems can be solved. If cuttting the pipe suggest a pipe cutter not a hacksaw, assuming you have enough clearance behind.

Alan

[Roger Mills]

You need a fairly powerful blowlamp, and you also need a heat-mat (or whatever they are called) immediately behind the joint. This will not only protect any adjacent woodwork from the heat, but will also reflect the heat back onto the fitting - enabling you to heat it more completely.

As others have said, once it is hot, try to rotate the pipe in the fitting to free it.

Roger

[BillR]

I would second that. If you don't get the joint apart within a reasonable time of first applying the heat, to go on doing so only makes matters worse

[sro]

If your blow lamp is low powered you may have a problem - what kind of blow torch is it ? If there is any water around you will have a problem. The idea of flowing new solder in is a good one - it proves that you are achieveing the required temperature and may well help to conduct the heat to the problem area. Cutting the pipe may not be so bad - you can buy end feed connectors that will slip right down the pipe so you dont have to pull the pipes apart to fit it.

Steve

[Chris]

Thanks Steve and everybody else who has replied - It seems the problem was with the blow lamp. I have been out and bought a new one and it seems to have done the trick.

[OldScrawn]

solder joints again.

and push fit are even easier