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re Re: When rust is found...

Date: Tue, 19 Jan 1999 20:31:27 -0500
From: Robert Myers <rmyers@inetone.net>
Subject: Re: When rust is found...

Geo wrote:
>Perhaps someone with a chemistry degree could explain just how this
>'snake oil' works.  Mr. Myers?  
And Bob Myers wrote:
>Well, first ya gots to ketch a buncha them thar snakes an' then...
The first product of this type with which I am familiar was advertised in
mechanical design magazines in the early 70's.  LoxRust was a brownish
chemical that reacted with rust to form something else that was relatively
inert.  It was designed for prepping rusty bridges and such.  It works well;
I still have some.  However, when the price of chromium skyrocketed, perhaps
due to boycotting SA, the producer stopped making it.  More recent products,
such as Extend made by Permatex, seem to have a similar chemical bound in an
acrylic paint.  This leaves a thick protective film which precludes its use
on exposed automotive sheet metal that the owner wants to look polished.  I
have also observed problems with it under the industrial epoxy I used for
undercoating my Corvair.  It seems to work well on my front-porch railing.
Automotive parts stores have a variety of chemicals for this purpose, that I
presume use similar chemistry, and that are intended for use in paint
finishing.  These should not be confused with phosphoric acid, the principal
component of prepping liquids such as Metalprep, and the active ingredient
of Naval Jelly.

For surface finishing of our Audi's, wash, use wax remover, sand, use wax
remover, wash with Metalprep or equivalent, wash with Galvaprep or
equivalent, then prime with a suitable primer, zinc chromate or an epoxy
based equivalent, although red primer seems to work if you are using
lacquer.  I believe one of our fellow lister's is an auto painter and can
provide a more refined, and possibly more up to date description.

                .... Kirby   (Kirby A. Smith)
                              2 x 1988 90q
                          New Hampshire USA