I just grabbed a compressor from a fridge that had been badly mangled by a bulldozer at a demolition site, planning to make a vacuum pump or airbrush compressor (or both!)
Trouble is, I thought the liquid it contained was leftover refrigerant, and drained it all out. I didn't really have a choice, as leftover freon was gassing out of the compressor (thought it had lost pressure, but there was still a little in the compressor) and it was sputtering the oil everywhere. I held it upside down while carrying it home, and when I got it here, it was apparently empty.
Then I found out that what I poured out wasn't liquid freon, but actually vital oil that keeps it alive. The compressor runs fine, but I only tried it for a few seconds for fear of destruction.
I have many lubricants here, motor oil, 2-stroke oil, bike chain oil, etc.
If I'm to dump an oil into my compressor, any ideas on which is the best call, and roughly how much should it take?