Reheating and rotating 22mm end feed copper.

I have a 22mm to 22mm to 15mm end feed Tee.

I want to rotate the 15mm pipe, which has a close fitting elbow connected.

The 22mm connections will remain untouched.

I can't see how I can localise the heat to just the 15mm connection, and I suspect the 22mm's will get hot and the solder momentarily melt.

I have reheated fittings before, but split the fittings apart, cleaned and refluxed.

I'm not sure if I have room to pull the fittings apart.

Any suggestions, I will clean around the matings, and apply flux, should I attempt to melt the solder in the 22mm connections and feed a little solder in, and then just leave them to cool after I have rotated the 15mm fitting. Or should I try keep heat from the rest of the fitting to a minimum.

 

If all you are doing is twisting the pipe in the fitting then you'll get away with it 95% of the time, especially if its a new joint. As long as you don't touch the 22mm ends then should be ok, just heat the 15mm pipe say 20/30mm away from the fitting.

 

Yes thats all I'm looking to do, thanks, I guess as long as the solder on the 22mm ends doesn't reach melting point - then ther integrity of the joint should be good then.

 

Even then, as long as you don't overheat the joint the solder should re-set without altering the integrity, the issue is when it's over heated and starts to bubble.

 

the issue is when it's over heated and starts to bubble.
I'm using MAP gas, but must admit I don't recall ever seeing it bubble - what sort of torch would make Solder do that, but in essence - where that does happen, your suggesting that can over cook solder then ?

 

You can burn solder. Wrap some wet tissue close to the 22mm, to keep that cool and have some sort of lever in the 15mm ready to turn it just as soon as it melts. Done it lots of times without problems.

 

You can burn solder.
Interesting to know that can happen, presume that happens where you leave the flame on too long ? tricky business trying to apply an even heat some times, especially in cramped spaces, and you have to rely on heating the front only and wait for the heat to get to the the back of the joint, and then wait for the capillary of the solder to run round the back, always prefer to give it a little more time and heat to ensure the solder runs all the way.

Does burn't solders surface take on a particular characteristic so you know when that has happened.

I will use old wet rag - didn't suggest that as 22mm seem to require more heat than 15's.

 

As said....keep the heat down...Use flux.

 

Yes.

 

The second you start to see bubbles from the solder then the fitting is stuffed as the solder has been overheated.

Heat the pipe that you want to move 'slowly' while putting a twisting motion on it, once it's hot enough the pipe will 'snap' loose & get it into position quickly and remove the heat. Don't apply heat to the fitting .... the 15mm pipe should go before the 22mm ends are hot enough.

 

Don't apply heat to the fitting
Or I presume, not try to put anymore solder in the joint ... simply heat, move, heat off.
Presume cleaning the area and wiping flux around prior to heating wont hurt.


Does burn't solders surface take on a particular characteristic so you know when that has happened
YES
Is there any particular 'trait' for the characteristics of burning that are visible ... ? dried crystalised surface, charring, etc

 

It changes colour, but before it gets there it start to bubble as gasses are released. Just heat the pipe gently until it 'snaps' loose. Don't have the torch heat up too high.

A typical DIY/newbie mistake is having the torch blasting away, especially if using MAP gas. It's not needed.

 

A typical DIY/newbie mistake is having the torch blasting away, especially if using MAP gas. It's not needed
Any idea how much hotter MAP gas is, I've changed back to ordinary blue bottled gas (is it propane ?), don't notice that it takes that much longer to heat a joint to be honest.

 

Oh, it does - MAP is a much more concentrated and hotter flame. You can braze with them.

I have a pair of Rothenburger's, I gave all my little butane / propane torches away, apart from a really big one, which was good for melting bitumen.

 

MAPP runs at about 30% hotter than propane does, so you can overheat a joint using MAPP much easier and quicker than using propane.

MAPP is a bit overkill for copper soldering but when your experienced with it you can solder faster.