Re: Could you detail your 'fridge pump vacuum pump set up please?

Ok, pretty simple really. Cut lines and bend the OUTLET line pointing
straight up. Now take a short piece of tubing that fits over the outlet
tube and put it on. Now run down to the auto parts store and pick up one
of those clear fuel filters that screw apart. Remove the filter element
and put it back together. Install it on the outlet line. Now fill it
with refrigerant oil. Might want to put another small filter of some
sort on the outlet side of that filter housing to keep out dirt. Now run
down to any appliance store and pick up a refrigeration service valve.
Be sure to get the correct size as there are a few different sizes of
lines on these things. The type I picked up was a sweat on saddle valve
that required the end of the line to de pinched off ans soldered. 
  In operation the oil in the outlet side will keep it lubed and sealed.
The clear filter housing acts as a nifty visual "guestimate" flow meter.
When the oil stops bubbling, you know it has pulled all it's going to
pull. If you need to you can always attach a real flow meter to the
outlet side of the oil resevior/visual guage.        
  I'm told that refrigerator pumps are designed in a manner that they
don't cool themselves all that well without freon flowing through them
and that continuous use is not advisable. I'm also told that freezer
pumps will stand continuous duty well because they are designed
differently. Don't know myself, but in practice I've pumped down A\C
systems and left my fridge pump running for hours and never had a
problem. However, if you have the option the freezer pump might be the
better way to go. A\C pumps like those used in home systems naturally
move a LOT of volume, but I'm told they need freon flow for cooling
worse than fridge pumps and are not at all well suited to continuous
duty. Again here say. Either way, these pumps generally wind up in a
land fill so if you don't salvage them, so you don't have much to loose
if you toast one. 

Good luck, have fun, and be careful with those high energy toys! :-) 

davidhosking wrote:
> Hi,
> I saw your post on the tesla list and as I am currently thinking of
> building a co2 laser and need a vac pump
> i thought this might be ideal.
> Kind regards,
> David Hosking
> Pharmacist,Amateur scientist, Pyrotechnician & Tesla Coiler.
>  "Be very careful what you put into your brain
>   because you will never get it out!"