On Sat, 01 Mar 2008 19:29:23 -0800, Larry Jaques
wrote:
On Sat, 01 Mar 2008 10:30:44 -0500, with neither quill nor qualm, bear
quickly quoth:

Ok, there is metal content.

I managed to get a former refrigerated trailer, that was last used as
a rental storage unit... anyhow it has a small diesel engine (nice!)
directly coupled to what looks like a two lung compressor.

Now here's the question, WHAT is/was used as lubricant for the
compressor unit??

This is a 30 year old trailer - so whatever was used then is
most likely in there now.

Back in the day, I did auto A/C repair. We used a special refrigerant
oil which was absolutely moisture-free. It circulates within the
system and does not evaporate in air any more than engine oil does.

Plain mineral oil based refrigeration oil. The only thing that made
it "special" was in the preparation and storage to keep it clean and
moisture-free, and it had a specified ISO weight and chemical
compatibilities.

-- Bruce --