Date:         Sun, 6 Apr 2008 08:26:44 -0400
Reply-To:     Karl Ploessl <karl.ploessl@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Karl Ploessl <karl.ploessl@GMAIL.COM>
Subject:      Re: failing brown plastic parts in early vanagons was: Re: pick n
              pull
Comments: To: John Bange <jbange@gmail.com>
In-Reply-To:  <6da579340804051756k6bf48ac1y613b9b854e58596a@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

I must be one of the lucky ones: my brown rear view mirror is still solid :-)

Karl.

On Sat, Apr 5, 2008 at 8:56 PM, John Bange <jbange@gmail.com> wrote:
> > I think, the chemical engineer, who designed the mix for the plastic, has
>  > made it for early disintegration, as planned obsolescense.
>
>
>  Nah, it's not so much "on purpose" as it is "cheap". I once had a plastic
>  and rubber guy explain the chemistry of it to me. I don't recall the
>  specifics because I don't know one long chain polymer from another, but the
>  practical upshot was that black plastic uses a more UV/ozone resistant
>  (plastic chemistry stuff) which happens to be black in color. In non-black
>  pieces, a different (plastic chemistry stuff) which is  white/clear has to
>  be used to make it colorable, and that stuff is a lot less UV/ozone
>  resistant. Additional chemicals can be added to make non-black pieces more
>  durable, but it's usually too costly for things designed to be relatively
>  cheap to make (like car trim parts).
>
>  --
>  John Bange
>  '90 Vanagon - "Geldsauger"
>



--
Karl
1981 VW Westy "Jenny"
2000 VW Jetta GLS VR6
Wilmington, DE