[Amps] Degreasing Ceramic

[Harold B. Mandel]

In the paragraph below do you actually mean trichloroethylene
or do you refer to 1,1 Trichloroethane (Methyl Chloroform)?

The former, trichloroethylene, smells completely different than
the chloroform. The latter was commonly known as "IBM Cleaning
Fluid," and was removed from all service.

The last cleaning fluid used in copious amounts at IBM was
Perchlorethylene (dry-cleaning fluid), used to melt off the
flux on chips left by the wave-soldering machine. The chips were
immersed in boiling Perc for a while and then transferred to
a vapor tank where perc condensed on the chips and dripped
off.

My lab had a Freon boiler. We would soak our ceramics in
a tank of boiling Freon, or rather just above the fluid level 
and the mist would degrease the surfaces. The nastiest job 
was when someone dropped a thousand or so chips into the
boiling Freon and had to scoop them out by bending over the
top of the tank.

Trichloroethylene is the nastiest smelling of all the stuff above.
Trichloroethane smells pretty good, but it's chewing up your
insides faster than the ethylene. Perc snuffs out your brain cells
as does the Freon. Mix handling these with responsibilities
handling radioactive isotopes and you can see why we had
plant-wide evacuations about once a month. 

There's a huge class-action lawsuit of ex-IBM'ers who got sick
using Cleaning Fluid. I think I read that some 5 out of the 20
who initiated action have died along the way.

If you're going to degrease ceramics using solvents at least do
it outside where the fumes can't be sucked into the furnace register
and be turned into Phosgene gas....

Respectfully,

Hal Mandel
W4HBM



> When in doubt, I always use 99% alcohol or even 
> MEK or (1,1,1 Trichlorethylene) but the last two are really bad SH_T 
> and you  don't want it lying around!