Message-ID: <36E80AF1.5A5E774B@innercite.com>
Date: Thu, 11 Mar 1999 10:26:57 -0800
From: Steve Colwell <colwell@innercite.com>
Reply-To: colwell@innercite.com
Organization: Ms Colwell
To: a <lancair.list@olsusa.com>
Subject: Methylene Chloride vs Acetone
Mime-Version: 1.0

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Having worked for the petrochemical div of a oil co many moons ago I learned
a few things.
   
Methylene Chloride is a strong solvent for oils and waxes.  It is strong
enough to attack foam and some resins if used in sufficient quantity to
accumulate rather than flash off.  This stuff IS toxic and should be used
with gloves & ventilation (I use my shopvac mounted outdoors to assist).  It
is by far the best cleaner for our purposes. Nonflammable

Acetone is a good solvent for waxes and very poor for oils.  Less toxic than
MC and Highly Flammable.  Which brings me to the pressurized misting of
Acetone, I advise against it.  Much higher vapor pressure than gasoline and
its the vapor that burns/explodes kids.   

If you want to test any cleaner take a piece of plate glass and wash it with
dishwashing soap.  Then smear on oil off your face and nose at the end of
the day, add some car paste wax next to it and some motor oil.  Wipe with a
paper towel dampened with the cleaning solvent and hold it up to a light. 
MC does a good job, Acetone will just move the oil around.  

While I am holding forth on cleaners, the best way to clean is to hold a
damp (not dripping) folded piece of paper towel in one hand and a dry piece
in the other.  Wipe one pass only with each side of the towels closely
following the damp with the dry to avoid the flash off drying of the
cleaner.  Turn the towel pieces to a fresh side and make ONE PASS.  Give the
parts plenty of time to dry or use your heat gun to accelerate the process
particularly on prepreg honeycomb or suffer fisheye.    Steve Colwell