I don't think that product is junk, hardly.
I am nutty about stopping rust, and I'd say preparing the surface is
extremely important.
I like to treat rusty metal first with 'rust prep' ............Osphro is a
famous one.
I use 'loctite Extend Rust Neutralizer'.........produces like these turn
rust to primered metal.
Of course you get all the loose stuff off first.  I just use a wire brush
basically, either a power wire wheel or a small hand wire brush.

Conditions matter too.........high humidity and low temps are not good.
Getting it really down in there is a task too, like deep in cracks.
But I bet if you prep it really well, use a surface etching or 'turns it to
primer' product first, or whatever POR recommends ( I think they have their
own product to do that ) ............and get 'all' rust spots way down in
the seems, and work in dry warm conditions...........it'll be on there
forever.
Darn, my POR Brochure is not at my fingertips, but I'm sure it's not 'junk'
.  You do need to use anything like that properly.   I would expect
something to be applied before the POR paint to prep the surface more.
Getting the product to bond  with the rusty metal, rather than just cover
it, is the goal.
Scott
www.turbovans.com

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Larry Himli
Sent: Friday, January 11, 2008 3:43 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Seam Rust & POR

I don't want to start another thread but recently there was one regarding
seam rust.  Some of you were pretty vocal that POR was junk!  Previously I
didn't pay much attention because it wasn't a problem for me.  However,
several years ago when the subject came up consensus was that POR was a
miracle for this problem.  I bought some of the materials and was planning
to fix several spots in the near future.  Should I or shouldn't eye.

Larry

87 Westy