Date:         Mon, 16 Aug 2004 15:27:42 -0400
Reply-To:     vw4x4@FYI.NET
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Eric Zeno <vw4x4@FYI.NET>
Subject:      Re: Rotor thoughts
Comments: To: Kim Brennan <kimbrennan@MAC.COM>
In-Reply-To:  <A1AEB5F4-EFB5-11D8-B9AA-000A95D4810A@mac.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

KIm,
      The only way to tell if the manufacture cut corners
in the alloy in the materials is to do a chemical analysis
of the material. Obviously I'm not going to do this.
 OR by finding that several people are having the same
problem from the same provider, etc. that of witch may
be coming out of this list server, currently.
Measureing or seeing the rust in a picture, I'm not sure
what this will prove.  One thing is for sure, these are
un-safe and will not pass state inspection.  Anyone want to
see these?  I'll be glad to send them a picture.
                                            ERic

Kim Brennan wrote:

> Okay, let's give this some thought about Rotors.
>
> They are made out of steel (not iron). Steel is an alloy of iron and
> carbon (often times with a few other miscellaneous additives). Steel
> (and Iron) will oxidize (rust), given exposure to Oxygen. Certain
> factors will accelarate this rusting such as salt.
>
> What can be done to minimize this rusting? Well the typical solutions
> are to coat the material so as to prevent exposure to Oxygen. This is
> impractical (paint) or unsafe (oil/grease) with brake rotors. Brake
> rotors are an ablative surface...i.e. it intentionally wears as it is
> used. This removes the rust from the wear surface. it does nothing on
> the other surfaces.
>
> Other ways to prevent rusting are to make the rotor out of non-rusting
> materials. Stainless steel is not a good choice as it's thermal
> characterics are horrible (it would warp or crack far too quickly.)
> Porsche has ceramic rotors. Incredibly expensive. Also somewhat
> fragile.
>
> Eric says his rotors are poorly manufactured. Most listees with
> experience find this a doubtful statement. It is not impossible
> however. Until or unless there is photographic evidence and micrometer
> measurements to support this, the rest of us will likely never know.
>
>