Just talked to a company selling a product called Glacier Gold Refrigerant. I'm a little leary - sounds too good to be true. They say it is compatible with R-12 and R-134 so can be used to top off both systems. It can replace both refrigerants using 6 oz of their's to replace 16 oz. of R134 or 18 oz of R-12. They say it is compatible with ALL oils. They claim it is colder than R-12 and the compressor works 30-40% less as their product is easier to compress - resulting in more gas mileage and longer life for compressors. It's apparently hygroscopic so small amounts of moisture in the system will be absorbed so it won't damage compressors or components - no need to draw a deep vacuum - 5 inches as opposed to 29 (charging into a deep vacuum will result in an overcharge). Best of all it is only $10 a 6 oz can or is available in 30 lb cylinders. It is totally enviromentally friendly and requires no license in USA or Canada to use. Their website (not very good) is http://glacier-gold-refrigerants.com/
with a link to their parent company.
HAVE I DIED AND GONE TO A/C HEAVEN - OR IS THIS A SCAM???
They say they have been selling it for over 3 years now. I would appreciate some input. If true it sounds like a godsend for DIY.