PROPER PROCEDURE FOR PAINTING RUSTED METAL

[1993_VG30E_GXE]

Can someone briefly tell me the best way to ensure a good slow down for further rusting of say the lower support member below the radiator and AC Condensor. My engine bay is empty and I want to treat these rusted areas with paint if possible.

This member is quite rusty under the radiator. Stuff I currently have in stock is:

DEM-KOTE RED OXIDE PRIMER / 70131F
DEM-KOTE ENAMEL FINISH / 70112
RUSTOLEUM RUST REFORMER / 215634
LOCTITE SOLVO-RUST SUPER PENETRATING OIL / 81252

I find this rustoleum stuff isn't that great. I tested it on the rusted rear wheel hub baffle plates, and within a week rust was starting to show through the rust reformer coating alone.

Tonight I scraped the member with wire brushes and jamming it with a big chisel to get the loose rust off, after first spraying it with the penetrant.

 

[blackdiamond]

I don't know about the paint vs. rust, but use a good solvent like acetone (maybe brake cleaner) to remove the penetrant or the paint will never adhere properly.

 

[demarpaint]

Clean, degrease, degloss, remove as much rust as possible. Get a red lead type primer for rusted surfaces, apply at least 2 coats of that, then finish with a metal paint. Once rust gets a hold on metal the best you can do is keep it at bay with a good prep job, primer and paint. HTH

 

[ikeepmychevytoo]

Sand it to a shiny (to the naked eye) finish. Impregnate with phosphoric acid (e.g. DuPont Quick-Prep). This is to dissolve micro rust pores. Then the two component epoxy primer. Zinc-chromate epoxies would be very good but those are highly toxic. Check originally wax filled areas with the body manual of the specific vehicle if there supposed to be wax.

 

[mechtech2]

New parts of may be easier/ cheaper than detailed complicated coatings.
I would not use any oil.
Scrape/sand/wire brush/etc. the best that you can. Maybe a sandblaster is handy - great.
Then use plain spray Rustoleum in a number of light coats after wards.

 

[Kestas]

Been there, done that. Painting may slow it down for just a bit, but the rust will continue. Wire brush as much scale as you can off the area, then treat with a rustproofing compound.

 

[1993_VG30E_GXE]

How do I treat those internal areas on the back side of metal that I can't reach with paint or rustproof. Is there some attachment to an HVLP paint gun that can snake into those access holes?

Even if I treat the exterior surface, the other side is still rusting away right?

 

[Kestas]

Yes. But now I wonder if you're not obsessing too much over the rust, for a car that sees winter salt. (I've been there too, obsessing). This is essentially a losing battle. Winter salt consumes vehicles, there is nothing you can do about it. Once you're done with this project, take your car over to Krown and let them do their magic.

 

[1993_VG30E_GXE]

It's true Kestas - I've been obsessing about the rust. I started peeling back areas in behind the rear seats and found rust holes on the wheel well when I was doing my struts. I've now purchased a whole MIG setup to patch those.

And ya, it's a losing battle with rust - but I just love doing the repairs and buying more equipment (I bought a MIG setup this yr too). I should do the Krown thing, I was thinking about that.

 

[tom slick]

If you really want to paint over serious rust then you need to use a 2 part epoxy paint to totally encapsulate it. It's the same stuff used for ships and off-shore oil rigs.

 

[1993_VG30E_GXE]

Tom can you do me a favour when you get a chance and look at the Fluid Film website. They claim that their marine products penetrate into the 'base layer' of the metal to go into the pores or something.

So my question to you is, is it better for me to de-scale the existing rust then coat it with Fluid Film (and obviously no paint) OR do the painting step that you say...applied over the dry rusted (but de-scaled) metal. I've found the 2 part products you speak of from DUPONT (IMRON), ENDURA, and RUSTOLEUM (Industrial).

 

[jef1ge]

http://rustbullet.com/

http://www.por15.com/

 

[tom slick]

IIRC fluid film is an oil product that coats. That is probably the best option for rusty metal but will require ongoing maintenance. If you want it to look painted then you need a paint. you'll need to get the paint as clean as possible for paint although a real epoxy paint can adhere to and encapsulate the rust.