Warning, longish.
Boy, have I heard a lot of different stories on this, and there are
several chicken/egg dilemmas that can just paralize you. I know, I
been there, and with paint on my little Datsun Truck, I'm still not
sure if I did it right. There may not be "One Right Way"
Check and see if the primer has a limited working window. Some do,
some don't. Referring to step #5, how do you paint right after
priming if you need to block the car 4 times in order to get the
waves out? After blocking you'll be wet-sanding with 600 or so grit
paper, so won't that cause moisture absorbtion?
Over a long period of time I pounded out dents, welded in patch
panels, etc covering it with rust-oleum primer to protect from
moisture. When I got it reasonably smooth I used a variety of
unpleasant methods to remove the paint to bare metal.
I used an etch primer on clean bare metal I used scotchbrite for a
final abrasive clean, then some pre-cleaner and many lint free
towels, then sprayed with the etch primer I used an HVLP gun and a
supplied air hood.
Here I got mixed messages between the Dupont can and the counter
man. Can said I could use the etch primer as a moisture corrosion
barrier. Couner man said no. I believed the can.
I then sanded the etch primer to bare metal where needed and added
filler,smoothing out. The Dupont can warned against using the etch
primer on plastic filler, and there were bare metal bands around the
filler repairs. What to do? Use an artist's airbrush to take the
etch primer up to the feather edge of the filler? C'Mon! I rouged
up the surface lightly with scotchbrite pads and laid down about 3
coats of filling primer. Then proceeded to block out the car using a
long flexible sanding board and 180 grit paper. Found low spots,
some needed more primer, some needed more filler. that went on for
awhile. so unless you're on speed and unemployed I can't see how you
can get a topcoat on "right away. Aftger blocking was done the car
was wet-sanded with 600 grit wet-dry with a small flexible sanding
block. Took over a week, so again the painting right away doesn't
add up.
Then three coats of single stage urethane.
Here's a website with an active forum and some sharp folks.
http://www.autobody101.com/
-Marc
On Apr 17, 2006, at 10:54 PM, Stan wrote:
>
> 1) Use phosphoric acid to clean and take off the surface rust.
> 2) Use a metal conditioner
> 3) Next spray with etching primer
> 4) Then use a top coat primer such as an epoxy
> 5) Paint right away as primer absorbs water and causes rusting if not
> painted
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