A/C O-ring lube

The service manual says to lube A/C o-rings and threads with 525 viscosity mineral oil. It specifically says to not use PAG oil.

I can order 525 mineral oil through Buick for $21 (amount unknown - probably a quart - way more than needed).

NAPA has 500 viscosity mineral oil for $10/quart. The label says for R-12 systems and lists Grand Prix through 94. Is that oil acceptable for a R-134a system?

Are there any other lubricants that can be used?

Never used it, but someone told me about it....can't see buying a quart of mineral oil.....

http://www.acsource.com/nylogsealantpnrt201bblue.aspx

Are there any other lubricants that can be used?[/QUOTE]

Ester oil.

Gonna use R-12 refrigerant oil that I already have to lube o-rings. Bottle doesn't identify it as "mineral oil" but I've seen R-12 oil online identified as mineral oil. I'm thinking should be fine just to lube o-rings.