How to Fix Rust Spots On a Car

Step 5: Prime, Paint

When applying paint, it is important to spray thin coats and keep it even. The paint that I was using was really nice, and went on very smoothly. I ended up spraying three coats of primer, waiting about two minutes between each coat for it to tack up. I let that sit all night and sprayed the paint in the morning. I had to spray the paint on even thinner, because it really wanted to run and sag. I ended up having five coats of paint on top of the primer. That gave me a nice color and a nice finish. I let it set at least 24 hours before I pulled off the tape.

The paint turned out pretty well, and it just looked like little patches over the old rust. The color wasn't quite the same as the old, but it was pretty close. It also had no clear coat on it, so it had a little different finish. I didn't bother buffing the edge of the paint so that it blended with the old paint.

Comments

[BrianJone5]

For your first body work, this is excellent. Certainly better than my first attempt.

Aerosols can't deliver the flake, so you'll never get a match. If your mask was outside the paint area (i.e new paint over good paint around the repair) you could soften the line with rubbing compound and a microfiber cloth.

One thing to add to your next repair is a degreaser. This is a solvent that removes all the wax and grease and road grime everywhere you want the paint to stick. They sell it where they sell the paint.

My second suggestion would be to 'feather out' your sanding. Try to sand each layer to an inch-wide stripe. This gives you less of a step to deal with in filler and paint. Change to a less aggressive abrasive and smooth it all out.

Most importantly though, you have stopped the rust in its tracks, and from 20 feet, no-one can see the repair. BTW with older cars, one way of assessing their state is in feet: "Its a 20-footer" explains how close you have to get to see noticeable defects. As you might expect, a 10-footer would be in really good shape.

[Rishnai]

The fact that the new paint is not metalflake is really annoying when trying to paint any metalflaked car. Of course, since yours was mostly just a quick and dirty rust repair, it's okay. My Milan is metalflake silver, and I had to paint a spot where, promptly after buying it, someone keyed it. Then I managed to open the door into the mirror on my dad's car, making more horrible scratches and dents which required a large area of sanding and repainting. Of course, the patch paint the dealership sold me wasn't metalflake, so in just the wrong light the repair is obvious and still drives me insane. Moral of the story: non-matching paint can suck.

[one_fake_user]

I don't know if it is the same in all countries, but in Australia you have a plate in the engine bay that states the VIN, engine number and paint code. If you take that paint code to an auto parts dealer, they can make you up a spray can of the right coloured paint. Depending on the age of the previous paint job and condition of the paint in the surrounding areas, it should be an exact match. The places around where I live do a spray can with 20mL of paint for approx AUD$30. If you have a spray gun you can get 250mL in a tin for the same price. But for small jobs the spray cans are ideal.

[Rishnai]

Thanks for the tip! I finally talked to a local auto-paint supply store and discovered that here in the US (dunno about in Australia), the paint code is on a sticker inside the driver's side door. They loaded up a spray can of the proper metallic, and now the door's good as new.

[renzo24441]

Even then, you have to still take into account the wear of over 20 years of UV damage to the original paint... It would be VERY difficult to match... at that point, you might as well want to respray the whole car... Looks like a great job, just "funny" looking because of the patches... reminds me of my younger years and the jeans with the patches on the knees.. hahaha

[one_fake_user]

Glad I could help. Was it very expensive for the metallic where you live?

[Rishnai]

No, actually. All of the auto paints formulated to match factory paint cost the same. As I recall, it was $40 for a pint(~470 mL), and $12 per spray can that they loaded, no matter how much paint of what sort was in it. I bought a pint and put half in the sprayer and half in the tin, since I can always come back and have them pressurize another can, but once a can is pressurized, you're stuck with it even if the proppellant leaks out.

[wonkette]

 $40 per pint comes out to $320 per gallon; I wonder why automotive paint is so expensive.

[ryguy425425]

The raw materials that are usually used are more expensive then those used in most house paints, especially if it is a metallic paint. Also, I'm willing to bet that if you did buy a gallon, it would be a lot less. (Considering two quarts of house paint cost more then a gallon here)

[one_fake_user]

Just a tip for next time. If you key up the area around the place you are painting with a nylon dish scourer, before you clean and spray it, the paint will stick a bit better and shouldn't flake off after a while. Also, if you don't mask the area as tightly, you won't be left with the distinct lines from the repair job and it will blend in a bit nicer.