Re: Aircon leak
I wouldnt try a bandage type repair as the gas will always find a way out.
I did a fix on my old Mondy although it was a flexible pipe that had split due to it rubbing on part of the chassis. I cut the flexible pipe and inserted a piece of copper tubing that was a snug fit. I attached this with two jubilee clips on each end done up very tightly with a ratchet.
On this basis you could try cutting out a small section of the metal tubing (be very careful not to get any swarf or muck in the pipe work) and then fix a suitable piece of flexible pipe in the gap (overlapping by a couple of inches both ends) with a couple of jubilee clips at each end very tightly done up. The pipe needs to be a snug fit over the pipes.
The danger is getting some muck or worse, swarf from cutting the pipes in the system, as this will mess up the compressor.
Ideally you should talk to an aircon speciallist who may be able to source a replacement first. Bodge jobs aren't always ideal but they do help to keep my washing machine going.