Anyone ever use this stuff?(freeze 12)
' this winter as a project.... if  ever get the time.. I'm looking at repairing my AC system on my 77;
Anyone ever use that stuff? it says it's a direct replacement... any additional info / how-to's on AC?
I'm a competent weekend mechanic that's done clutches engine replacements and head-gaskets... that type stuff......
is there any advise on converting if need be?
thanks timg

I actually spoke with a tech at the Freeze 12 manufacturer...wasn't impressed with any of the answers I got.
I bought a case of it once, and read some of the tech data...it can be used, but...I wasn't satisfied with the end results. It is supposed to be a "drop-in" replacement for R12, but it's really not. If you completely re-do the entire A/C system, it will work better...otherwise, it is just a stop-gap. Basically a good deal for used car lots, nothing more.
You're better off switching over to 134a.
My 2c...

If freeze 12 is not a good answer... how hard is the swap to 134a?

I agree with Joel on this. Freeze 12 is 80% 134a and 20% 142b. Certainly doesn't sound like drop in. The "12" in the name is simply misleading. Convert to 134A or find some R12. It IS still available, found 12 cans on ebay. Came to about $17 per can including shipping. Need to get licensed to buy it but it's a simple test that costs $20. My certification came from Mainstream Engineering.  Mike

Much smarter move to do the 134a conversion. I too studied the Freeze 12 data years ago. I was not at all impressed with the data and was less impressed with the answers received from the tech rep. It clearly is not a direct replacement for R12. I converted my Vette and old Pickup to R134a. I have not been disappointed.
Good Luck,
Scott

[QUOTE=timgman] If freeze 12 is not a good answer... how hard is the swap to 134a?
[/QUOTE]

Not that hard, actually. Drain all the oil out of the compressor, unless you are installing a new one, in which case it will be dry anyway. Flush the system with A/C flush really well, and then blow it as dry as you can. Replace the dryer(if you have one...'77 was a "change-over" year).
Put the correct amount of oil in the compressor, evacuate the system for a hour or so(more is better, here), check to see that the system will hold the vac. for a while(again, more is better), and then charge it with 134.
To be PC(and legal... ), you will need to put adaptors on the fittings, so R12 equipment will not fit.

Flush Blow and vacume?
do I need specialtools for this? how can I tell if I have a dryer?
is there a procedure page on the net? Ifthere is I have yet to find it ;)
I'll make one .. I swear ...

how about this stuff?
http://www.icorinternational.com/hotshot_opening.html

First step is to recover any R12 that may be in the system, this will require a refrigerant recovery machine ( to be legal ).  You will need a vacuum pump to do proper evacuation.  This boils off any moisture in the system prior to charging with new refrigerant.  Vacuum is not the best leak detection method as it is only a force of 14-15 PSIG.  The system will be exposed to much higher pressures when it is operating.  A standing pressure check with dry nitrogen is the best method of insuring a leak free system.

Tim, take a look at THIS THREAD...it has some good info on doing this.