Re: RUST

["Fred Munro" <munrof@isys.ca>]

-----Original Message-----
From: Shane Allen Snyder <snyders2@pilot.msu.edu>
To: quattro audi <quattro@coimbra.ans.net>
Date: Tuesday, January 20, 1998 12:01 PM
Subject: RUST


>My Audi is suffering from some ugly surface rust in the usual places.  In
>October, I sanded the areas as best I could without removing trim pieces.
I
>applied 3 coats of primer and 3 coats of paint.  Still, in about 50% of the
>areas, the rust as returned worse than before.  I would appreciate some
>suggestions on how to get rid of this rust for good (or atleast a few
years).
>I have heard about products that convert the rust to a stable form.  Any
>suggestions would be greatly appreciated!!!
>
>
>--
>
>*---> Shane Snyder (snyders2@pilot.msu.edu) <---*
>
Hi Shane;

    They use so much road salt here that no matter what colour car you
drive, it is white all winter! As a result I have had a lot of experience
with rust repair on various biodegradable vehicles and, since body repair is
not my favourite activity and I hate doing the same job twice, I have found
a procedure which gives excellent results. Unfortunately, there are no
shortcuts and yes, you usually have to remove the trim.
    One of the reasons I bought my first Audi was the galvanized body - I
foresaw a blissful release from body repair and I haven't been
disappointed! The Audi bodies stand up very well.

The Procedure:

1.    Sandblast to bare metal, including a "halo" of good metal under intact
paint around the rusted area.

2.    Treat the bare metal with a phosphoric acid-based metal conditioner. I
use Dupont M-3 metal conditioner.

3.    Base prime with an epoxy-based wash primer such as Dupont Corlar.

4.    Top prime with a two-part urethane primer such as Dupont 1020R.

5.    Topcoat with good quality paint. I find Dupont's Chromabase
basecoat/clearcoat system easy to use, easy to match, and very durable.

    I use the Dupont paints but other paint companies make similar products.
I have never had a re-rust failure using this procedure. Good sanding and
surface prep procedures are very important to the durability of the job.
    I have tried the Loctite product which "converts rust" but it does not
give long-lasting results.


HTH

Fred Munro
'91 200q  245k km