I guess this was my point....
Rust cannot be "fixed" from the outside.... or .... the inside.
It lies on the 1/2" or so flange...
In the middle.
Yes, you can stop the problem that caused it in the first place.
The influx of water from inside plumbing from the water tank, tubing, sink etc.
You can reseal the windows, the Camper Outlets, whatever.
You can spray the rust oxidating compounds,
and hope they penetrate as deeply as possible. ( wouldnt count on that 100% )
But the rust Is Still there,
No matter what, until the seam is seperated and sanded, cleaned,  prepped and re-sealed.
YMMV
JC...

-------------- Original message --------------
From: JordanVw@AOL.COM

> In a message dated 3/20/08 6:40:04 PM Eastern Standard Time,
> greenvanagon@GMAIL.COM writes:
>
>
> > Has anybody used POR Patch as a seam sealer?
> > http://www.imperialrestoration.com/products.php?category=8#18
> >
> >
>
> if you smear this stuff on your outside seams without fixing the real problem
> - the point of entry of dirt and water on your seams from behind - then it
> will only conceal the rust eating the metal away and when you finally do see
> the damage it will be alot worse.
>
> dont mask the problem. fix it from behind.
>
>
> **************
> Create a Home
> Theater Like the Pros. Watch the video on AOL Home.
>
> (http://home.aol.com/diy/ home-improvement-eric-stromer?video=15?ncid=aolhom00030
> 000000001)