[TowerTalk] Fwd: Re: WD-40

[Howard Hoyt]

AB2ZY said:

>> "...I was wondering what  the "magic ingredient" in ATF was that
 >> busted rust..."

The factors contributing to ATF's penetrating and antioxidative 
performance is due to the additive package, which makes up up 15% of ATF 
by volume.  Consider that in an AT, there are clutches which must not 
slip excessively, and yet they are bathed in ATF.  This characteristic 
is achieved by a stout surface-tension friction modifier package.  The 
anti-oxidative package is designed to keep the many aluminum and steel 
parts in close proximity from forming dimetallic corrosion cells.  In 
addition there are detergent and anti-wear packages which contains 
molecules structured as micelles, one end which is oliophilic and the 
other end is hydrophilic.  These molecules have a high affinity for 
metal surfaces while remaining suspended in the oil base.

Bottom line: ATF is highly attracted to metal, has corrosion 
neutralizers and very low surface tension, and the addition of acetone 
as a solvent base to lower the viscosity greatly assists the penetration 
of this soup into cracks and crevices.  Once it is there is neutralizes 
corrosion to a small extent, but also deposits anti-wear agents which 
help coat asperities with a film which assists release of the frictional 
interface.

We have seen similar results from small amounts (~5%) ZDDP dissolved in 
acetone, but I believe the friction modifier in ATF really boosts the 
wetting and performance in this application.


Howie - WA4PSC

-- 
Howard Hoyt - STLE/SAE/STC
Dir. of Engineering
ZPlus, LLC
www.zddplus.com