Here is my test Syncro.
http://syncrospecialist.com/blacksyncro.aspx
It had a horrible hippie paintjob until I sprayed it with flat black primer in the rattlers.
Everytime we go for a spin, when I return I touch up any dings from offroading.
Never sanded a thing, just keep on coating it.
Not what most would do, but I am surprised as to how well the primer has stayed put.
It was the 88cent per can flat black from WalMart.
I spent way more on beer.

dylan

________________________________
From: Mike S <mikes@FLATSURFACE.COM>
To: vanagon@GERRY.VANAGON.COM
Sent: Wed, October 14, 2009 6:12:11 PM
Subject: Re: is primer/sealer weathertight?

At 05:32 PM 10/14/2009, Florian Speier wrote...
>Obviously I have to redo a few things, but I was wondering whether my
>assumption that primer sealer is weathertight was wrong, or if I did
>the

Most primer is porous. I hesitate to say "all," as there are some, like
epoxy, which aren't. A friend of mine once prepped his whole car,
primered it, and left it - planning to get it painted in a couple of
weeks. It was all rusted well before then. As I recall, he got so
discouraged, he ended up just using rattle cans. It didn't last a whole
lot longer.