Originally Posted by dieseldan44

Questions for the experts -

(*) 1.) Can I use MIG welding gas (75% argon, 25% CO2) as my inert gas for the pressure test? I ask because I already have plenty of it.

2.) For the deconversion, I need to go back to R-12 fittings. How can I tell if I have damaged anything by taking the 134a fittings off? That isn't entirely clear.

3.) For the blowing out of the lines with air after the flush. If I use my air compressor with an inline desiccant and oil/water separator - is that OK? Even if there is a tiny amount of moisture that gets through, won't that boiled out during the vacuum step? (I could use welding gas here, but I don't want to waste it)

thanks, looking forward to learning to do this the right way...
dd