Found this in rec.bikes.tech, cross posted from alt.mountain-bike. Thought it would be of interest:
----- Original Message -----
From: "Gary J. Harris" <email@example.com>
Sent: Wednesday, November 28, 2001 7:53 AM
Subject: Simple Green & Aluminum Mountain Bikes
> Presented for your consideration:
> I've seen a number of postings from mountain bikers that
> use Simple Green to clean their bikes and/or components.
> I myself used it as a general cleaner/degreaser on my bike
> but have discontinued the practice since I came across
> reports that the US Army and Air Force had prohibited its
> use on their aircraft and other equipment. Now you can
> think what you like about the Army and Air Force or even
> the US government in general, but when it comes down to
> taking care of its equipment, they have a pretty good
> The AOPA (Airplane Owners and Operators Association) has
> also come out recommending against its use. Airplanes
> constitue a pretty big investment and they are not cheap
> to repair and maintain. The AOPA is a private group not
> usually given to putting out bad advice to their members.
> Aviation-grade aluminum is pretty expensive stuff. The
> paint used in painting aircraft is usually very high
> quality and much more durable than auto paint, and
> probably the paint used to on bicycles. I don't have
> any credentials in metallurgy but I do know that aluminum
> bike frames in particular are touted as being high-grade
> aluminum. Other components are made of aluminum as well,
> like cassettes and handlebars. I also seem to remember
> the words 'aviation grade' used in describing the
> materials used in some bicycle parts.
> So between the the US Army, the US Air Force, and the
> AOPA, I think their advice on this issue is worth
> considering. There are enough other products available
> that do as good or better job than Simple Green that this
> should not be a showstopper for anyone.
> Below are excerpts of some of the inforamtion available
> on the web:
> Aircraft Cleaners
> Simple Green and other cleaners that are not listed in the
> Technical Manuals are taboo for a very good reason - they
> hurt the metal used to build the machine.
> It has been brought to the attention of the U.S. Army
> Aviation Missile Command (AMCOM) Depot Maintenance
> Engineering Team that numerous units are using the
> commercial product SIMPLE GREEN as an aircraft wash.
> STOP! This product has been through Department of Defense
> (DOD) testing and was determined to be highly corrosive
> on aircraft aluminum and also a catalyst for Hydrogen
> Embrittlement in high strength aircraft alloys.
> While a highly effective cleaning agent for floors and
> non-aluminum / non-high strength alloy vehicles this
> product is not approved for aviation usage. If your unit
> has been using SIMPLE GREEN on a regular basis, it is
> recommended that a thorough fresh water wash with the
> approved cleaners per the appropriate airframe maintenance
> manuals be accomplished as soon as practicable. This
> should be followed up with a corrosion inspection /
> treatment and application of approved Corrosion
> Prevention Compounds (CPCs).
> Mr. Richard Cardinale, firstname.lastname@example.org
> (361)961-4041, DSN 861-4041
> AOPA advised caution with any cleaner and stated that "No
> cleaner should be left on an aircraft for an extended
> period; any cleaner should be promptly and thoroughly
> rinsed off the airframe with water."
> It's Simple -- Don't Use This To Clean Aluminum
> A well-known aviation magazine this month published a
> feature article on cleaning one's aircraft and getting
> it ready for spring flying. Only one problem -- a product
> the article recommended as safe for aviation use has been
> proven corrosive to aluminum. The product is Simple Green,
> a popular household cleaning liquid. According to the
> magazine's May issue -- which included a photo of Simple
> Green and other products -- the liquid "does an admirable
> job for a fraction of the cost of the aviation cleaners."
> While that may be true as far as it goes, both the U.S.
> Air Force and the U.S. Army have conducted tests of Simple
> Green and strongly urge that it not be used to clean
> aluminum structures. In one test conducted by the U.S.
> Air Force, results from which were published in 1989,
> aluminum alloy samples were immersed in Simple Green for
> a week then removed, cleaned and weighed. The results
> indicated that the approximately 3.5-gram aluminum alloy
> samples experienced a material loss of about 31 milligrams
> in a diluted solution and a whopping 295 milligram loss
> after spending a week in the undiluted liquid. The Air
> Force report summed it up this way: "We do not recommend
> the use of this product on Air Force equipment containing
> aluminum." Good advice, that.
> Gary (the other Gary from Virginia)
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