Message-ID: <36EC0B2D.8A200772@mc.net>
Date: Sun, 14 Mar 1999 13:17:01 -0600
From: jerry@mc.net
Reply-To: jerry@mc.net
To: lancair.list@olsusa.com
Subject: Isopropyl Alcohol & Sanding
Mime-Version: 1.0

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What a great forum this is with nearly immediate answers from hands-on
experienced builders.  We are all blessed.  My thanks Marv.

To everyone out there:

What does isopropyl alcohol clean-up?  What will it loosen or dissolve? 
Does it dissolve oils...petroleum oil as well as skin oil types?  Is
isopropyl alcohol used in conjunction with other cleaning agents?  What is a
water break test?

Why shouldn't we be cleaning the bid target area before we rough-up with the
sanding operations?  It seems to me the smoothed areas from the molds would
be easier to clean up before it gets sanded.  

Trying to clean an already sanded area seems more difficult.  The sanded
area has too many microscopic "pits and grooves" to reach into with solvents
and then lift them with dry towels.  

What am I missing in this cleaning operation?  From what I read in LML,
cleaning with solvents seems to take place after the sanding.  If there are
contaminants on the smooth surface being sanded, where might they end up? 
If they are oils and waxes, they could end up in two places.... 1. ground
into the roughened bid area and 2. accumulated on the sanding media to be
distributed elsewhere with the next sanding operation.

I read from various sources, bid failures are common problems in fiberglass
airplanes.  It seems the "fix" for this encourages a thorough sanding of bid
target areas.  I can't fault this thinking.  I hasten to add .....thorough
sanding has to include thorough cleaning sequences and procedures with
appropriate cleaning solvents.

Find the fun.....Jerry Grimmonpre'  L320