Just for the record:

 >a rusty bit on the lower left corner (when facing front of van)

is almost always a hole underneath the rubber.
Mostly right next to the seam below the windshield and looking as if it
just crawled out from under the rubber. There might even be a hole
without water entering he Van (happened to me...see
www.v6bus.de/Bild005.jpg)

That powder might be talcum, see http://en.wikipedia.org/wiki/Talc for
this. A powder  that is used in combination with rubber, like in camping
mattresses.
It is used to keep things dry, to keep rubber soft etc.
In combination with rust it might get tan.

I think this is a sign that your windshield has been removed or
replaced, VW didn�t use talcum to insert the windshield.

Raimund

Rocket J Squirrel schrieb:
> Good questions.
>
> Original windshield and rubber. I have neither the courage nor the skill
> to pop the windshield to replace the rubber. There is a rusty bit on the
> lower left corner (when facing front of van) that will need some
> attention
> from someone who knows what he's doing, will need to call around town.
> May
> replace rubber then, who knows?
>
> Back to your questions:
>
> No leakage during rain noted. The affected rubber does receive a lot of
> direct sunlight through the glass. No similar weird powder noted on
> outside of rubber.
>
> --
> Mike "Rocket J Squirrel" Elliott
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> Bend, OR
> KG6RCR
>
>
>
> On 8/19/2009 11:27 AM Jeff Lincoln wrote:
>
>> Mr. Squirrel,
>>
>> I wonder if this is the remnant of some kind of seal epoxy or
>> lubricant used
>> to install the window. Then again you think it would be common if
>> that were
>> the case.
>>
>> Does the windshiled appear to be leaking during rain? Is this the
>> original
>> window seal?
>>
>> I'm just throwing that out there because - well I'm curious to see where
>> this goes. I've never experienced it.
>>
>> --
>> Thanks,
>>
>> Jeff
>> '90 Carat (Grover)
>> '86 (We call this one Parts)
>> '78 Bus (Melissa) Patty's Bus
>>