If you haven't done this kind of thing before, I'd reccommend an HP book
with the title of 'paint and bodywork' or something like that. [HP books
can be found in chain book stores out here, and most of the titles are
how to hot-rod/rebuild your small/large block ford/chevy/chrysler/honda
engine // dune-buggy // brakes // electrial system]
It's a drag if you don't have air tools, but basicly, you've got a couple
ways to remove rust: (air tools are lighter to hold & easier to work with,
'cause you don't have an electric motor attached, an equivalently sturdy
electric device is much heavier) [if you can find a local tech HS with
an adult ed autobody class, it might be worth taking it just for access to
the tools, material & shop time... like I'm doing now]
always wear safety goggles and a dust mask.
sanding/grinding wheels (like 16 and 40 grit) they tend to take things
down to shiny bare metal, unless the 'surface' rust is particularly
nasty. (instinct tells me putting a sanding/grinding wheel on most
electric drills would kill 'em.)
3m, (our friend) makes these wonderful wheels of this spun polymer,
they cost $5-6 at your local hardware store, and they wear out, but
they're really neat. (requires a durable drill)
wire brushes are good for knocking rust loose, but, IMHO, they lose
when compared to either of the above, (though could be used before
the polymer wheel). (requires a durable drill)
Once you've got bare metal, you need to clean the area, Dupont's
got a product called 'prep-sol', basicly similar to some form
of paint thinner. (pending a compatible paint, fast drying laquer
thinner will do the same thing).
Now you've got clean bare metal (rust city awaits), then you want to
cover it.
(now the serious car restorer uses an epoxy based primer, then a
primer filler, while your local body shop should
apply something to etch the metal (makes the primer adhere better,
but is usually acidic, leading to (long, long, long term hydrogen
embrittlement, which is why the serious car restorer doesn't etch
or use self-etching primers))
If you so desire, apply something to prepare the metal for priming,
Dupont's product is called Kwik Prep, and, well, it is a mixture of
alcohol and phosphoric acid, (read and obey warnings) Some of us who
are less intelligent use a plant-sprayer-squirt bottle, hold our breath
and run the other way while it's drying.
In theory, if you use the above, you don't need a self-etching primer
like DuPont Vari-Prime, a two part primer which requires mixing
before use (within a couple days), and that too contains all kinds
of nasty organic things which evaporate, paint things, and phosphoric
acid. (of course, it also requires a spray gun). (Vari-prime is also
a zinc-chromate based primer, so it dries to the wonderful coloured
puke-greenish-yellow.)
Now, that you've got primer left, it needs to be top-coated, as
primer is somewhat porus (sp?), and will let water penetrate the
primer and attack you so-carefully-cleaned metal. In my bad
experiences, I've seen primers w/o metal etching show signs
of rust in a couple days (when wet). Spray-can primers w/
metal etching managed to last till they got good and wet,
vari-prime seems to be a little more resistant, however, it
will eventually rust through given wet/salty-wet conditions.
Of course, all these fun and environmentally hazardous dupont
products are available at your local body-shop supply store,
(bring cash, most don't lots of business to retail customers).
--bill
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