How to solder 90 deg bends near walls

[henry1]

I have a copper pipe going up a wall, then through it and up again. The pipe through the wall is sleeved within another pipe to protect it from corrosion and wall movement.
How do I solder both elbow fittings at each end of the pipe that goes through the wall? Part of the fitting is slightly within the wall. I could solder one end by removing it from the wall first but I still need to solder the other fitting in situ. I can't make the hole larger or deeper as there is another pipe there as sleeve.
How do the pros do it?

 

[ianmcd]

Experience and practice mostly, assuming it is a water pipe so why not use tectite push on copper fittings, slightly more expensive but very easy to use

https://www.screwfix.com/p/tectite-sprint-copper-push-fit-equal-90-elbow-15mm/6486g

 

[Nige F]

Or use a Yorkshire elbow

 

[Madrab]

If it's a brick and plaster wall then it will be relatively undamaged for the time it take to heat the fitting out from the wall and then move the heat to where it needs to be, especially if you wet the wall.
As @Nige F mentions too using a Yorkie (solder ring fitting) would probably be the best idea if you want to solder.

 

[henry1]

The problem is not about the wall being damaged but the lack of access to direct the flame where needed as the joint will be slightly within the wall.
Yorkshire fitting might work if I can see the ring of solder being formed. Not sure if I can see that far.
I've seen such setups with end feed fittings, so I wonder how they do it.

 

[oldbuffer]

Call the elbows A and B.
Solder A as normal (out of the wall), but first tin the end of the pipe going into B with solder, and wipe off excess.
Clean the elbow for B, and use a spare piece of pipe, solder the spare into the elbow, then remove. Reheat elbow and remove excess solder.
Flux the tinned end of the pipe in the wall, and push tinned side of elbow B onto it. Heat, and the solder will flow.
I'd pressure test before connecting into the main run.

To be fair, its not much different from using a Yorkshire fitting.