I also say “Kleenex” I’m so not a pro with my hvac vernacular.
I think I’m going to try soldering the thing, then pressurize it, before ordering a new condenser. Lead free solder is tough stuff if you can do a good job and the pin hole seems pretty accessible. Maybe 15 mins invested so far so not much to lose even if it fails after a few weeks.
While reassembling, I noticed a wire for the fan pressing against what I thought was an indentation due to a rock. So it wasn't a rock. Factory workmanship defect.
It's 4 screws - super easy - to remove your grill and check for this. If I were reading this, I'd check.
Good call on giving the solder some thought. Most contain silver or tin, which will corrode and not bond with the Al.
Aluminum is a pain, just took me a bit to recall, as I don't do this every day. The melting temperature of this solder is close to the aluminum itself, and the solder is probably beefier... I was barely able to get this together. The tube was caving in and all seemed about to be lost, but I got a blob to stick - but alas - it's still a cold joint. Pressure test went okay - not a highly visible leak - but the UV die could be seen making its way through the joint after some run time. Too busy right now to swap condenser. I guess there's a reason everyone calls these things unrepairable.
I would have cut away the finning. You don't need every last square inch of surface area, and it would have helped your heat situation. Did you scrub the aluminum with the solder as you heated it? You need to do that to break through the oxide layer - the flux won't do it on it's own. You can also watch your temps this way. The solder will "crayon" onto the aluminum before the aluminum melts.
If that wouldn't have worked and I stubbornly wanted to succeed at this I would have sacrificed the tube - cut out the bad segment and then end soldered the tube stubs.
This isn’t copper and 400 degree Sn/Pb or Si solder. Keep in mind the solder here and the condenser melt at about the same temperature, 1000 degrees. You won’t get back behind those cooling fins with solder wicking either without vaporizing everything.
I am aware you are soldering aluminum. There are also much lower melting point aluminum solders. Very near regular 50/50 Sn/Pb temps. Harris sells one. Belmont makes another one. What you are using sounds like a high temperature braze.
There was nothing local other than what I got and my confidence it would work regardless was low. It’s not a material so much for brazing as it’s just a cheap and Chinese consumer grade item. I might consider a for real solder and flux, we’ll see, so busy now and tired of maintaining things.