[Vwdiesel] Re: R12 replacement (follow up)

[bobs at chemdec.natsci.csulb.edu]

I think I may have stirred up some AC purists when I mentioned flushing an
evap and cond with water & acetone.  An explanation may be in order:

I got the idea from my over 25 year experience servicing/maintaining mass
spectrometers and electron microscopes.  The internal parts (source,
quadrupole, ion trap, etc.) of these instruments must be "vacuum clean". 
Otherwise there will be an unacceptable background level.  Even a partial
fingerprint will render a mass spec useless.  I learned long ago that the
easiest way to obtain vacuum cleanliness is by first scrubbing the
internal parts with BonAmi and tap water.  Next I rinse with distilled
water.  Finally I use spectro grade acetone to dry the parts before
re-assembly.  During re-assembly I use clean lint free gloves.  After
re-assembly the entire assembly gets baked in a vacuum at a temp of about
300 to 350 deg C.

I figured that if this method can get parts vacuum clean, then it
certainly would be sufficient for a refrigeration system.

By the way, the working vacuum in mass specs and an electron microscopes
is obtained by using the same type (roughing) pump as is used for
refrigeration service.  An additional pump (either a diffusion type or
turbo molecular type) is used to obtain what approaches a perfect vacuum.

Bob Soukup