>If you have two pieces of  metal apart you can use a "weld through" primer
>that will allow you to coat the surfaces before spot welding back together.
>
>This would be better than going back together bare metal.

It would help, certainly, so lone as it really resisted burning
during welding. I know that some red-lead primers are extremely
heat-resistant, and will burn only at the weld. Of course rust will
be free to resume at the welds...

>I believe the vw body metal has a flash plating on it before its asembled.

 From what I saw of Golf 1s in Newfoundland, they seemed less
rust-prone than most cars.

>I think there are quite a few good rust products like the Por-15 camp that
>offer "liquid" converters that would work into seams well.

They all claim to "turn the rust black". That's not what I see when I use them.

>I had thought a bit of rust sealed off from any outside moisture would
>"stop" or be severely "slowed" to the point where you could get the service
>out of the vehicle anyway.

Yes, slowed is the operative word. However condensation can produce
suffiecent surface water to run down the inside surfaces of the
vehicle, soaking the seams. And if salt is in there too...

The best solution would be to cut all the seams open, REMOVE the
rusty metal and weld new metal in to replace the seams. Then there
would be no seams to redevelop rust. Ideally when buying a new
vehicle you could do what rallyers do... strip the car down to a
naked body and seam-weld them. But who's gonna do that?
--
Andrew Grebneff
Dunedin
New Zealand
Fossil preparator
<andrew.grebneff@stonebow.otago.ac.nz>
Seashell, Macintosh, VW/Toyota van nut