Sure. I wasn't trying to be a jerk, I just don't think Ed's question was "which refrigerant should I use, and is it flammable and/or legal" and he got several responses in that vein. Many other threads have covered those topics.

Thanks, jurgen.

Indeed. anyone in the denver area (or scottsdale for Ed) have a vacuum pump?

There should be an off the shelf refrigerant with equivalent performance to an 80/20 mix propane/isobutane. There's no reason I can think of that would prevent this product. I thought the enviro safe stuff was about 80/20 propane/isobutane, but I guess it's propane and cyclopentane, from the MSDS:

http://befreetech.com/esmsds.htm

In any case, I will probably be willing to pay a little more (and possibly sacrifice a little performance, but probably not) to have the convenience of R134a style charging rather than the propane rig. It is very interesting to see you guys doing custom rigs, though.

Anybody know anything about the cyclopentane?

TIA

If someone is trying to make this type of decision, they should at least be able to search the board. If they did, they would have found MANY other threads with opinions on various refrigerants.

Should each thread address every aspect of the system? Should a thread on rebuilding engines cover every possible tradeoff and choice of building every possible engine (2.0-3.8, cams, cylinder composition, bearings, valves, pistons, etc, etc. ad nauseum)? I don't think so. If someone is trying to solve a complex problem, they should do their homework.

anyway, please see my previous post for something on-topic regarding HC refrigerant compositions.

Nah Kobalt. I haven't found anything with the higher propane percentages. But I have heard that enviro-safe has something with a little more propane than usual. They say it's called the industrial blend. Don't know for sure though. Now I have to find someone locally with a vacuum pump.

Yeah, Envirosafe has an R22 replacement product as well, which is probably the industrial product you are referring to. I will probably use their R12 replacement and just see how it works.

I haven't searched for rentals on vacuum pumps, but it sounds like it may be tough. I guess I might try the old refrigerator technique posted (Thanks, vin!).

On a side note, I drove my '92 968 6-spd coupe today, which has a never touched R12 system. Damn that's a nice car, with ICE cold AC :D

It would be really great to see a performance comparison between the Enviro-Safe and/or Duracool and an 80/20 propane/isobutane mix. It might be possible to estimate with some educated guesses on proportions, plus the MSDS.

(edit: What I meant was it might be possible to estimate the relative performance with some educated guesses on the proportions of gases for which ranges are specified in the MSDS.)

Kobalt, I have a lot of news. First, I bought a full case of enviro-safe today. After all, it's cheap. I had plenty of fun playing with ac today. From the same guy I bought the enviro-safe from, I also bought a basic charging hose. This charging hose has a r134 can tap and an r12 end piece to connect to an r12 schrader valve on the compressor. He has all types of hoses and side tap combinations if required. I also got some stop leak. The enviro safe, like everything today, comes in an r134 type can, so that's why I needed a mixture of connectors. I got it from this place www.azaircare.com. The guy's name is Jack. I almost bought the standard enviro-safe, but then he told me about the industrial stuff. Standard ES12 is at best a 60/40 mix. But the industrial is 70/30. I bought the 70/30. It comes in taller cans. The guy is a previous 911 owner who is feeling the bug again. I forgot what I paid since I just gave him some cash and went on my way. Regardless, it was cheap by r12 standards.

Well, here is what I did since I got so much of the stuff anyway. First I took the car to a friend who took out almost all the freon in it. Just left a hair to keep some pressure in there. I just put in a full can at first, then let the compressor run. Just barely cool at the vents. Needed more. After that, I got out the benzomatic propane and added while watching the gauges. While the gauges were looking good, my wife inside the car holding 2k told me the temp at the vent was going just below 60. I quit there since the car was parked, the ambient temperature was around 105 farenheit, and the condenser is small. So I shut off the car, removed the gauges and took off down the road. Mind you, I am no ace when it comes to AC charging. I just know the safety basics, but not the nuances of gauge readings. I am sure that if some AC buff was messing around there, he could have lowered the vent temps another 10 degrees. Well here are the results after a quickie five minute ride on the freeway. At 105 ambient temperature, on the freeway it got down to around 45 and was still going down when I pulled off the freeway. Down the street it stayed at around 45. When parked, the highest I got was 60. Keep in mind the ambient temps. For me those are fine. My sister drove it said that's fine for her considering how f'n hot it was outside. Maybe I'll take it over to a buddy of mine's house this weekend so he can play with it. He is good with AC so I'll let him see if it needs more. Good stuff this propane.

Here is how I rigged the Benzomatic tip.
http://forums.pelicanparts.com/uploa...1086315270.jpg

First I got an r12 hose at an auto AC supply place. I cut one of the ends off. Then I got this adaptor thingy at Home Depot in the compressor accesory isle in the tool department. The tough part was getting the hose to go on that nipple. That's as far as I got. I'll try to push it in further tonight. The brass nipple I attached to the Benzomatic nozzle by using epoxy putty. It sealed real well. After all, I have used this stuff to seal boat hulls. Tough stuff. Just make sure not to block the holes on both ends with the Epoxy. Another alternative is to wrap some plumbers sealing tape around the Benzomatic tip and thread it into the nipple since there are threads on the inside. That should seal pretty good. I got no leaks on mine. Don't forget the drilling that Steve mentioned. It worked good. I'm happy. I think this is one great refrigerant. No pollution either.

I just put two cans of Dura Cool in my '87, works fine. It comes in a can exactly like the old R12 did, even has a little lube oil in it.

Nice, Ed, thanks for all the feedback! I'll be doing something pretty similar soon. I guess since you left a tiny bit of freon pressure, you didn't have to vac the system when you put your gauge set on.

Others: please do not tell us again about the legality issues of this. Ed and myself have both done our research. Thank you.

Sounds good guys. I can't wait to get my AC working again. I have a Cabriolet, but would enjoy having cold AC for those really hot days!

Others: please do not tell us again about the legality issues of this. Ed and myself have both done our research. Thank you.

Okay.


http://forums.pelicanparts.com/uploa...1086356594.jpg

I hope all the Bozos (epoxy bonded gas fittings!?) doing this know the difference between the discharge and suction sides of their systems; in R-12 systems the fittings are the same. An exploding refrigerant cannister is bad enough without adding a fireball to the shrapnel.

Ed, I have vacuum pump, recovery equipment, refrigerant scale, etc. and live in Gilbert area.

Point taken, Jim. I plan to use regular fittings with refrigerant in proper cans, rather than any drilling out of fittings etc. etc. Ed does seem to have done well, however. Really, I was just trying to prevent a tirade on mixing of refrigerants.

When I bought DuraCool I was advised that the fittings were unique to their product so I bought there stuff. I never even bothered to check against my equipment.

I just bought a set of guages to check my system and for adding some Duracool I just bought. I could just add a can but wanted to use the guages to see the current condition. I am unsure exactly how to use the guages...do I just hook up the higher side guage to the high pressure side and the lower guage to the other. What is the 3rd/middle threaded connector used for then?
Pics would be helpfu...
TIA

The third hose is ? (yellow) used to install the product of choice into the low side via the control valve at the top of the ? (blue) hose. ? (red) should be the high side. I hope this helps. Never,never,never install on the high side, it will explode the container. If I am wrong sorry. I hope this helps. Mark

I know someone that has run 8oz. of C5H8 in his car all last year and it worked good, now it needs the correct amount I think 12 oz shoulds work, but he is going to go back to r-12 or duracool now.

sometimes the FD gets notices from the fire marshals about industrial freons being used in cars and it being an explosive high risk..

So if I understand I just hook the high side hose to discharge side, the low pressure hose/guage up the the suction side and the yellow hose to the Duracool can. Can I just hook up the low and high guages to see what the pressure is now or does something have to be hooked up the the middle threaded opening to keep from venting the system?