2004 Corolla roof rust woes

[zorobabel]

I'll start with 2 photos taken 10 months ago, the front side of the roof.


It has gotten a little bit worse since then.
I think they scr*wed up at the factory (US vin), since I see a number of Corollas of this generation with nice brown roofs

.
Obviously the proper fix would be to repaint the whole roof. But I'm looking at stopping the damage happening now for starters.
I'm thinking of doing this on the affected patches:
1. using some fine steel wool to remove the paint bits sticking out
2. then use acetone or mineral spirits to clean up the bits and pieces (I have a can of odorless mineral spirits, but the [censored] thing is not very good at evaporating)
3. use a spray can of Rust-Oleum Rust Reformer with the chair (http://www.homedepot.com/p/Rust-Oleum-Stops-Rust-10-25-oz-Rust-Reformer-Spray-215215/100392541)

The car paint is black, but I'm not going for the clear coat factory look, as anything looks better than rust.
What do you guys think?

 

[Nissan101]

honestly
it will take a good amount of time to complete rust, so just leave as is until you are ready to paint.
Or you can DIY.
With normal compress can spray paint.
Won't look OEM but still get the job done

 

[SZR48207]

Rather than spray, roll on the paint with some decent quality rollers and it should self level enough to look good. Plus it will be a thicker coat to withstand the elements. Spray paint goes on notoriously thin.

 

[Donald]

They sell a precise sanding pen that sands but does not enlarge the spot. I might do some of the worst spots with the sanding pen and follow it by some Loctite Extend applied with an artist's brush.

The entire roof needs to be sanded and painted at some point.

 

[zorobabel]

Originally Posted By: Reddy45
Rather than spray, roll on the paint with some decent quality rollers and it should self level enough to look good. Plus it will be a thicker coat to withstand the elements. Spray paint goes on notoriously thin.

Thanks, I'll keep that in mind.

 

[zorobabel]

Originally Posted By: Donald
They sell a precise sanding pen that sands but does not enlarge the spot. I might do some of the worst spots with the sanding pen and follow it by some Loctite Extend applied with an artist's brush.

The entire roof needs to be sanded and painted at some point.

Thanks! I am most definitely not going to do that on the roof, way too many spots. But it's a good idea for paint chips on the hood.

 

[Vern_in_IL]

Leave it alone!!

There is a guy driving a 1984 Grey Mercury Topaz that the entire roof and hood are rusted, looks awesome! Low miles since he only drives in town.

 

[Ducked]

Sunflower oil alone if you want to keep the patina but don't want holes in your roof.

Rubbed with crumpled aluminium foil if you want to enhance the protection and don't mind a patchy silvery grey. (I don't, but I'd guess you would)

Overpaint with black bitumen if you don't mind a roof that looks as if it was overpainted with black bitumen. (I don't, but I'd guess you would)

I'd put something over it to keep dust off. Takes a long time to dry.

 

[KGMtech]

Sand it down, paint it with some rust paint, then get a partial vinyl wrap done.

 

[Nick1994]

Sounds like a good candidate to take to Maaco for their $299 paint job special. If only the roof and hood need it, see if they'll just paint those two for the $299 if they throw in some clear coat.

 

[Ducked]

Looks like adherent plant fibres. Dunno what trees you have in the US but I'd guess it might have been parked near something with fluffy seeds, and maybe sticky sap to stick them on.

They would then attract and hold moisture and perhaps produce acids by bacterial action.

I'd wash those off before you do anything else.

 

[SeaJay]

Do I have this straight, the OP is trying to fix a roof on a 14 year old corolla to like new condition?

 

[eljefino]

Originally Posted By: Reddy45
Rather than spray, roll on the paint with some decent quality rollers and it should self level enough to look good. Plus it will be a thicker coat to withstand the elements. Spray paint goes on notoriously thin.


If you google around for the "$50 paint job" there's a procedure that involves thinning the roll-on paint, going six layers thick, and it dries rock-hard.

You will want it durable as the slip-stream up there will eat lesser paints.

 

[zorobabel]

Originally Posted By: Ducked
Looks like adherent plant fibres. Dunno what trees you have in the US but I'd guess it might have been parked near something with fluffy seeds, and maybe sticky sap to stick them on.

They would then attract and hold moisture and perhaps produce acids by bacterial action.

I'd wash those off before you do anything else.


The fibers are from a washing mit, and were caught up by the peeling paint.

 

[deanm11]

Originally Posted By: SeaJay
Do I have this straight, the OP is trying to fix a roof on a 14 year old corolla to like new condition?


The OP said: The car paint is black, but I'm not going for the clear coat factory look, as anything looks better than rust.

So, no.

OP: if it were me, I'd bite the bullet and do a home job on the entire roof. Sand (heavy sand.. no fine steel wool !), rust convert, couple coats of spray bomb color. clear optional, as you suggest. And I always get the clear coming out too dull from spray bombs. (I don't think the spray is fine enough and/or the clear dries too fast.)

 

[Trav]

You can do this at home pretty easily, it ont be pro but good enough to pass a acceptable.
Use an orbital sander on the areas with 36 grit paper, and the rest of the roof with 400 wet and dry,clean it good when your done wipe the bare metal with cheap vinegar letting it sit for 10 min (it gets any little spots in the metal that you don't see) then wipe with prep-all then mask the roof off.

Put 3-4 good coats of self etching primer on the bare metal letting it dry 10 min between coats then use a black sanding primer for 3 coats right over it and let it dry overnight.

Wet sand the black primer lightly with 400 and water just to flatten it out, prep-all again and re-mask, shoot it with black spray bombs. When using spray bombs imagine the panel in 4 sections, don't try and put a coat on the whole panel just one quarter of it then move down to the next section overlap slightly and go around it till you get back to where you started. Repeat until you have a few good coats on it, that's it. Don't bother with spray bomb clear on black it just cracks and yellows, it cant stand the heat on the roof or hood/trunk lid for that you need prof 2 stage clear if you were to use base coat which needs clear, the bombs you want are lacquer.

It sound like a lot of work but it isn't, most of the time is in the drying of the primers, you cant rush that as it will shrink. prime and paint in the late afternoon or early evening not mid day sun.

https://shop.advanceautoparts.com/p/dupl...l1677/7140452-P

https://shop.advanceautoparts.com/p/dupl...+etching+primer

https://shop.advanceautoparts.com/p/dupl...rm=black+primer

https://shop.advanceautoparts.com/p/prep...chTerm=prep+all

 

[zorobabel]

Thank you Trav!
I might have to do the whole roof eventually, and if I do, I'll paint it white.
Please clarify the bellow in red:
Originally Posted By: Trav
You can do this at home pretty easily, it ont be pro but good enough to pass a acceptable.
Use an orbital sander on the areas with 36 grit paper, and the rest of the roof with 400 wet and dry (so orbital sander on rust areas with 36 grit and rest of the roof orbital sander with 400 grit. Do I go to bare metal everywhere?),clean it good when your done wipe the bare metal with cheap vinegar letting it sit for 10 min (it gets any little spots in the metal that you don't see) then wipe with prep-all then mask the roof off.

Put 3-4 good coats of self etching primer on the bare metal letting it dry 10 min between coats then use a black sanding primer for 3 coats right over it and let it dry overnight.

Wet sand the black primer lightly with 400 and water just to flatten it out, prep-all again and re-mask, shoot it with black spray bombs. When using spray bombs imagine the panel in 4 sections, don't try and put a coat on the whole panel just one quarter of it then move down to the next section overlap slightly and go around it till you get back to where you started. Repeat until you have a few good coats on it, that's it. Don't bother with spray bomb clear on black it just cracks and yellows, it cant stand the heat on the roof or hood/trunk lid for that you need prof 2 stage clear if you were to use base coat which needs clear, the bombs you want are lacquer.

It sound like a lot of work but it isn't, most of the time is in the drying of the primers, you cant rush that as it will shrink. prime and paint in the late afternoon or early evening not mid day sun.

https://shop.advanceautoparts.com/p/dupl...l1677/7140452-P

https://shop.advanceautoparts.com/p/dupl...+etching+primer

https://shop.advanceautoparts.com/p/dupl...rm=black+primer

https://shop.advanceautoparts.com/p/prep...chTerm=prep+all



Is all the sanding done with the orbital sander?

 

[deanm11]

Trav is the expert, but... best to all bare metal & the orbital is just going to be fastest way there, but doesn't matter as long as you get it down to metal.

 

[zorobabel]

Klean Strip Prep All does not seem popular with local stores. What can I use instead, if I don't find it?

I have decided to go with the Duplicolor self etching primer spray first, then RustOleum dark gray automotive primer spray on top of that. I will stay with the black color and will roll RustOleum gloss black protective enamel on top of everything.

 

[Trav]

Originally Posted By: zorobabel


Is all the sanding done with the orbital sander?


No its just the quickest way outside of a fixed disc which you don't want to use unless prepping the metal for filler which you are not. I do everything after putting the primer on by hand with a rubber block, primers and fillers contain a lot of talc which makes them easy to sand and good fillers but also absorbs moisture which is why you use an etching primer under it, normally I use epoxy with poly over but that's getting into spray guns and fresh air respirators so its basically out for home DIY.

The electric orbital sander is just an electric DA which is a common body working sander for paint prep, keep the speed in the mid range not full tilt. Use plent of water with the 400 grit and rubber block and the primer will sand very quickly, if you go though its no big deal just let it dry and apply some more.
I wouldn't roll the paint on, it looks awful (if you don't care then that's fine), with a sanded primer job spray bombs will do a much nicer job and last just as long just take your time and ask questions if you find yourself stuck. PM me if you want as I don't look at every post.