Re: Rust Repair

[Mladen Sasic <msasic@freenet.npiec.on.ca>]

On Tue, 4 Feb 1997 KSMITH1@mailgw.sanders.lockheed.com wrote:

> I have used Extend on various objects, and suspect it would be 
> acceptable in a hidden area, but not on an exposed surface that one 
> would like the paint to meet even GM factory standards.  It is a 
> combination of a rust reactant and plastic film.  It is the film that 
> does not form smoothly, nor can it be sanded the way laquer can.
> 
> There was a great product called Steelcoat that was thin, and formed a 
> good surface reaction, but I think it was discontinued during one of 
> the inflationary periods when chromium prices skyrocketed.
> 
> The process I have used for surface prep, which I think is the 
> PPG/Ditzler recommended approach, is to sand, clean with Metalprep(R) 
> until there is no more rust.  Clean with Galvaprep(R) until there is a 
> film of zinc chromate (?), anyway, it looks flat grey/gray. Fill with 
> the appropriate filler (depends on depth of irregularities.).  Sand.  
> Do it again!  Prime, paint.  (Priming/Painting directions left to the 
> student.)  If done correctly, no rust will creep along under the paint 
> from an unpassivated rust point.
> 
> By the way, it was my impression that Audi started galvanizing in 87, 
> so rust on an 86 is not suprising to me.  Did they start sooner?
> 
> ***                 ...Kirby    (Kirby A. Smith)                 ***
> ***              ksmith1@mailgw.sanders.lockheed.com             ***
> ***              [=]   kirby.a.smith@lmco.com                    ***
> ***  Opinions expressed herein are entirely those of the author. ***
> 
I have 5kS 1987, and rust on the same spot :under rubber gasket, both
sides left and right, rear windshield. Also, I heve seen rust on many 5k
(including mine) above trim strip of rear bumper,left side.