When stainless steel gets hot, it changes colours.  It starts with a "straw"
colour (brownish) and changes to an eventual deep purple (at very high
temperatures).  Look at a custom SS exhaust on a Harley, and you can "see" the
temperatures of the exhaust gasses by the colour on the pipes coming out of the
engine.  In most cars, the exhast system is long enough that the gasses cool by
the time the get to the tailpipe, but the Vanagons is so short it might be hot
enough to discolour the SS a little (sure test is that the discolouration should
come off with Scotch brite or something scratchy).  The discolouration is just the
deepening of the protective oxide layer.  This is what it sounds like to me... the
different alloys might discolour at different temperatures.

Keith Adams
Calgary, Alberta, Canada
1986 Vanagon GL Westfalia

RAlanen@AOL.COM wrote:

> In a message dated 4/20/00 6:03:09 PM Eastern Daylight Time,
> LISTSERV@GERRY.VANAGON.COM writes:
>
> << Driving report - STEBRO Stainless muffler >>
> <<Only funny thing is that the tailpipe and entry pipes seem to be made out
> <<of non-stainless or a different
> <<kind of stainless, and got a slight rusty color after the trip.
>
> <<Don't know whether they are simply another SS alloy or not.   (Frank?)>>
>
>     Dave, I'm told by STEBRO that this is normal for the type of stainless
> steel used.  The Muffler body and tailpipe are the same 409 stainless.
>     From the technical specification on my STEBRO/Vanagon Stainless Steel
> Muffler webpage, <A HREF="http://members.aol.com/Fkc43/stebro.htm">Vanagon
> STEBRO products</A>, .....>"Stainless steel construction throughout with the
> shell, inlet pipe and tail pipe made from 14ga 409 and the baffles, connector
> flange, and hanger from 14ga 304"
>
>     Thanks for the report Dave.  I've added it to my <A
> HREF="http://members.aol.com/Fkc43/reviews.htm">Muffler Reviews</A> page.
>
> Cheers
>
> Frank Condelli
> '87 Westy & Lionel Trains
> STEBRO/Vanagon Stainless Steel Exhaust Systems
> Almonte, On