If you have the heating/cooling flaps installed and working on your engine
the demister should be OK.

With the flaps removed (very common) there is no pressure built up in the
fan housing and virtually no air is blown into the car's heater cahnnels.
With the flaps installed, when the engine is cold the flaps prevent most of
the air escaping over the cylinders and it is forced through the heat
exchangers into the car (and the demister).

Andrew.


"Birdlander" > wrote in message
. com...
> OK...I have a classically weak defroster in my 73 SB. Not a problem in
> the
> summer, but as it gets wetter/colder here in the midwest, things get
> difficult.
>
> So...is there some kind of solution I can treat the inside of the
> windshield
> with to help with this situation?
>
>