Date: Wed, 8 Sep 1999 10:29:19 -0700
Reply-To: Stuart MacMillan <stuart@COBALTGROUP.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Stuart MacMillan <stuart@COBALTGROUP.COM>
Organization: The Cobalt Group
Subject: Re: How are body seams constructed--spot weld or ??
Content-Type: text/plain; charset=us-ascii
All body panels are spot welded every half inch or so using flanges or
overlapped seams. No sealer is used during welding, and that is the
main reason they rust. Eventually the paint cracks and water gets into
the joint where there is plenty of bare metal to eat. The only
protection is paint, both on the inside and outside of the panel.
Some sealer/filler may be used on the seams before painting but I doubt
it--anything that adds to the time it takes to produce the vehicle also
adds to the cost, and all manufacturers try to keep that down.
Likewise, continuous welding would be extremely time consuming, and
leading the seams is cost prohibitive for all but the top end luxury
cars. Remember, the manufacturers design for a 10-12 year useful life,
they need you to buy another car on a regular basis to stay in business.
As far as repairs, new epoxy adhesives are often used now for joining
panels when the joints cannot be easily reached for welding, which is
most of them. I had my right front corner and the front panel replaced
last year, and they were glued in at the seams then welded at the
corners and the joint where the A pillar was cut. The glue is an
excellent seam sealer, and as strong as welding, theoretically.
My biggest problem with repairs is that the panels supplied by
aftermarket suppliers have a poor primer on them which should be
stripped and reprimed before painting. Most shops don't bother, nor do
they paint the inside areas which will rust almost immediately.
Rustproof these yourself.
Tim Marciniak wrote:
>
> Dear Listees,
>
> Recently there has been some posting regarding seam rust. Not really being
> familiar with all methods of joining autobody panels I was wondering if
> someone could explain to me how these seams for joining these panels are
> designed.
>
> Is there a 90 degree flange on each panel butted against each other that is
> spot welded then a seam sealer applied over it then paint?
>
> Or is it a continuous weld with a sealer over it, then paint?
>
> Or why didnt VW just make the seam invisble by welding it continuous with a
> butt weld and smoothing it over.
>
> Just understanding how this seam is designed/constructed may help me in
> fixing it.
>
> Thanks for your replies.
>
> Tim
> 90 Multivan
--
Stuart MacMillan
Manager, Case Program
800-909-8244 ext 208
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