I have, from time to time, needed a good vacuum source. Typically it's used to bleed brake or clutch lines. I put a vacuum on the fill tube and any air in the system gets sucked out. Other times I want a huge clamp that's oddly shaped, so I put a plastic bag over the parts and draw a vacuum on the bag. You can get about 13 psig on the bag this way, and if the thing has lots of square inches, it puts a LOT of force on the parts. This is how the better carbon fiber parts are made... they lay down the resin and fiber, then put a vacuum on the parts in a big bag, which squeezes most of the resin out.

Up until now I've just sucked it up (so to speak) and used my trusty Mity-Vac, and telling myself to think of it as doing a forearm workout at the gym. But like I've said, I had been thinking about an alternative for a while, so today I took the plunge. If you'd like to have a vacuum source for those types of things, or just to have it to crush cans and watch water boil at room temperature, here's what you need:

1) an old window air conditioner or refrigerator
2) tubing cutter
3) electrical tape
4) miscellaneous tools

Slowly cut into the inlet tubing of the compressor. It will probably leak out some freon and maybe some oil. After it equalizes pressure, do the same thing for the outlet side, but do this even more slowly -- this is the high pressure side.

Note whether the motor is capacitor start or not. If it has a capacitor, you'll need to keep it. Note the wiring to the motor -- there will probably be a hot wire going to the compressor after first going through a switch of some sort. The other wire is probably coming from the capacitor, if it's a capacitor start motor. There also may be a ground wire. That's it, probably 2 wires, maybe 3 going to the compressor. Before you get too deep into this, make sure the compressor actually runs. Start the A/C or fridge and if the compressor starts, then start the disassembly.

The compressor I got from an old window A/C unit can pull 27" of mercury vacuum. Perfect is 29.92", so this little thing sucks like there's no tomorrow []

This is just a really quick write-up, so if I've made any errors and something I've said seems wrong, please correct it. If you want more detail, just ask.

 

Maybe you could post this in the DIY section? It's an interesting idea. What do you call an air conditioner that can suck the chrome off a trailer hitch?....

 

DARLIN' !!!!!!

 

Dont let Al Gore know what you are dooing. Dumping refrigerent into the atmosphire is a big NO NO Big fines if big daddy finds out.

 

Fwiw, just about any kind of HVAC shop would be glad to reclaim whatever refrigerant is in your system.

 

Yeah, I should have checked out freon reclamation facilities, but frankly, I didn't think there would be any refrigerant left, since that's why we dumped the A/C unit.

I didn't see a DIY section, so I posted in the only tech section I visit. If a mod out there reads this, please move the thread as appropriate.