Ig-Lo R-12 Freon Refrigerant 12, 4 cans, $4.

DuPont R12 Freon Refrigerant (dichlorodifluoromethane) was used in many millions of cars, until its use was halted in the mid 1990s. Today, these little 'self serve' cans of R-12, which used to cost a buck at any department store, are highly sought-after by the people who really need what's inside.

Anyone who was driving a car back before the mid 1990's knows that good old R 12 Freon was used in all automotive air conditioning systems. Those older automotive air conditioner systems loved the stuff, and R 12 systems kept countless milions of motorists icy cold for many years.

The problem with R 12 is that it is a chlorofluorocarbon halomethane, more commonly referred to as a CFC, and has been implicated in the destruction of the ozone layer in the upper atmosphere. For this reason, it was phased out in the mid 1990's and replaced with another less-destructive refrigerant known as R-134, which is still currently used in many vehicles. As you can imagine, the remaining R 12 immediately disappeared from the auto parts stores, and nowadays it can only be found at air conditioning shops that are licensed to handle it.

In the years since R 12 was phased out, numerous companies have tried all kinds of replacements, all claiming to be 'compatible' with R 12. In other words, you're supposed to be able to just squirt the new replacement stuff into your vehicle's air conditioning system and it' will replace the R 12, or mix in with what's already there. What could be easier? Unfortunately, nothing has yet been developed that will fill the bill in that respect, without raising the spectre of dissolving seals, leaking hoses, seizing compressors and even catching fire. But, people are still out there trying the various R 12 replacements.

The downside to all this shade tree chemistry is that unlike the R 12 refrigerant in a 'virgin' a/c system that hasn't been monkeyed with, which can be simply extracted by an air conditioning shop and recycled, much of the garbage that the shops are pulling out of auto air conditioning systems nowadays is worthless in terms of recyclability. This is because it has been contaminated with any number of the R 12 'replacement' gases. The shortage of good, recyclable R 12 converts into really high prices for the unspoiled R 12 that's still available.

I guess one solution to the problem is to simply convert your R 12 system to use R134, right? There are even kits you can buy at auto parts stores that allow you to do so. However, any professional will tell you that it's not as simple as just purging the oil and changing a few seals, or even changing all the hoses. Unless you go the whole route and spend a bundle on a complete replacement of all air conditioning components, you're inviting problems. In short, there's no inexpensive way to convert an R 12 system to use anything else.

- But what about the guy who owns a car that still uses R-12 and just needs a can to 'top off' his system?
- What about the guy who wants to get that classic 1960's or 1970's car back to completely original condition?
- What about the poor fellow who wants to sell his older car, but the air blows a little warm and he just needs a little charge to pump it up so he can sell it?

Is there any option available to these folks, other than getting soaked down at the local automotive air conditioning shop?

As you can see, there's a wide spectrum of buyers for these valuable little cans of gas! And despite the rusty tops and the forlorn appearance of the particular cans I have here, what those avid eBay bidders out there are really after are the 14 ounces of pure, unadulterated, uncontaminated R 12 Freon in each can. Whenever you're at a yard sale where older automotive stuff is on the menu, always keep a sharp eye out for these beauties, because they're easy to miss if you're not looking for them!

Although prices for this stuff can vary widely, you can usually figure on from $25 to $40 per 12-ounce can.