Freon/oil/concerns?

[Gerry]

Condenser was on a Peterbilt, has been open to atmosphere for a couple months now. There was a thought of repair, but it was replaced, so this is part 'can it be done for next time' and part 'if I fix this, it'll make a nice piece for a TIG cooler.

If you going to use it for a cooler core, I'd just glue the clip back on. It's not going to take a beating like it would on the front of the Pete.
If you want to weld it, I'd do it outside, make sure the inlet and outlet ports are facing away from you and anything flammable . There is still possibly some oil/coating inside the condenser, wear a chemical respirator and face shield. 3 hail Marys & crossing your toes wouldn't hurt.

[sw2x]

If this condensor is removed and has been open for some time you could use acetone and fill the inside of the condensor half way and then shake the crap out of it for a few minutes and then dump it out and let it sit for a few days, then I would think you could weld on it without much risk. I assumed that you were welding on a residential or commercial condensor that was still installed and that is a recipe for disaster. Automotive style systems contain alot less refrigerant and alot less oil than your typical residential or commercial systems..

Why not braze it? I do similiar repairs all the time on Commercial package units in upwards of 50 tons using oxy-acetylene and some Sil-Phos 15% if your trying to attach dissimilar metals you can purchase brazing rods in 56% silver.
Using a Welder is very unorthodox, even the manufacturers use a brazing process except that they do use a electric machine that heats the fitting and melts the filler material into the joints...

[Rambozo]

You can also braze with a TIG. Comes out very clean and no long torch flame, so nothing around it gets burned or needs to be protected with heat shielding.

[jakeru]

I did some welding on an aluminum AC condensor, (putting back on a broken off aluminum fitting onto one for an old mini cooper). Yes, there is a concern regarding phosgene gas when sufficiently heating up (which includes TIG welding) anything chlorinated (including old-school refrigerants - but not the newer "nonchlorinated" ones, just as it does old school "chlorinated" brake parts cleaner and other solvents, but not newer "nonchlorinated" brake parts cleaners or other nonchlorinated solvents.)

I recall verifying that the refrigerant was nonchlorinated as a precondition before taking on the repair. Do some research on the subject for your own safety, and exercise caution. Not a bad idea to weld in a location having good ventilation and keeping your head well away from where any potentially dangerous fumes might be. That said, it welded up nicely. Not sure if I got any pics of it though.