Restoring a Rusted Roof

[gregski]

My 68 coupe had a vinyl roof. One of the previous owners ripped off the vynil to allow it to breath and minimize the water damage. The vehicle sat outside in northern California but the roof still rusted. I would like to share my attempts with you on how to remove the rust yourself.

My budget is $100 bucks a month to spend on the car, but that is to bring back the entire car to life, so please don't suggest I save the money for a couple of months/years and take it to a "reputable" shop to have it done. The point is to do it yourself and eventually paint it instead of vinaling it all over again. I do not have an air compressor, so I can't media blast it.

Your feedback and advice is very much appreciated as I have not done this before.

 

[KStang65B]

Phosphoric acid will clean it up nicely.

Spray it on. Let it sit (Don't let it dry, however. Respray as needed). Rinse and repeat if necessary.

 

[S-Car-Go]

Along time ago I had the exact same problem with a 66 coupe. I used a wire wheel in a drill and some navel jelly to get rid of the rust. Then removed the headliner and put fiberglass patches under the areas with holes. Once the fiberglass was fully cured, I bondo'd from the top. You couldn't see it after painting and I had the car ~10 yrs before I sold it. It never cracked or showed any signs there was a hokey repair there.

 

[mtaqua]

mine was worse and did about the same as s-car-go. where the rust was real bad I hit it with a wire wheel on a grinder. some spots I even put a sand blaster on (be careful with this not to warp, I only used it on the leading edges). Once the rust was gone I weld up any holes. Then used pickle-x to treat. Used Rage to make it smooth, epoxy primer, feather fill, and going to spray bc/cc tomorrow. Looking at it now the roof looks really good, we'll see if it holds up.

 

[gregski]

Then removed the headliner and put fiberglass patches under the areas with holes.

Luckily I don't have any holes, not even pin holes, the roof seems solid other than heavy surface rust. Kinda scared to use a wire wheel, that sounds too abrasive, we'll see.

 

[gregski]

Used Rage to make it smooth, epoxy primer, feather fill, and going to spray bc/cc tomorrow. Looking at it now the roof looks really good, we'll see if it holds up.

Any pictures?

 

[gregski]

Fight the Rust!

So first thing I decided to try was sand paper / sand sponges and handrollics and elbow grease. From Home Depot I purchased a pack of three sheets of 320 grit 9 inch by 11 inch sand paper and one Ultra Fine (grit unspecified) sanding sponge. Decided to go with that because of what I read on the internet, and I knew I could always go coarser but didn't want to start off with some media that would put holes in my roof, know what I mean Vern?

My buddy came over to help me fight the rust, and after about an hour of working said: "You're better off using paper towels!" meaning the grit is too fine on what we have. It was around lunch time anyways, so after picking up some tacos at Carollina's we went across the street to AutoZone.

Armed ourselves with some 9 x 11 inch 120 grit paper to cut up for our sanding block, and three different sponges: Green 60 grit, Red 100 grit, and Yellow 320 grit. The sponges are pretty cool if you haven't tried them already you might wanna, they conform to the shape of what you are sending fairly well.

Rust is a b-a-s-t-a-r-d, very difficult to get rid off by hand, maybe it could be done but I don't have months to spend on this doing it by hand plus it would take hundreds of dollars in media. After about 6 hours spent with these products wet sanding I think it is time to try some chemicals.

Using images off the web for the sponges because my camera didn't wanna focus on them when I took my pictures. Other's are authentic, LOL.

 

[gregski]

Vinegar

Well before following some of this sound advice, here's what we've tried. Vinegar, which did two things. First it evaporated, second it stunk up the garage, and didn't do squat in terms of rust removal.

 

[NasaGT]

Use a fine wire brush on a high speed drill or on a 4 1/2" grinder. That's light surface rust, it'll come off pretty fast that way.

 

[gregski]

RUST-OLEUM Rust Stripper

Next up was RUST-OLEUM Rust Stripper, a bit better than the vinegar but still as effective as sucking a titty through a sweater. Instructions said leave it on for 10 minutes. We gave it a bit more time, but all it did was expose some tiny bare spots here and there. It could be done, but we didn't have 50 gallons of this stuff. We only tried it on half the roof so we could compare the results to the sand paper side.

 

[Fordmus67tang]

It looks like light surface rust. I would use a wire brush like what NasaGT says or use one of those fiber glass wheels you hook up to an angle grinder. Just don't apply a lot of pressure. It should remove it quickly.

 

[RXTbone]

Did almost my entire car with a 19V cordless drill and a few of these. Cuts right down to bare metal without scratching the crap out of it...

 

[Fordmus67tang]

yup, those are the ones except I bought the ones for my angle grinder. Those things are great! rust old paint it'll take it off quick.

 

[Realmongo]

Roofs are not the thickest pieces of metal so I would hold off on abrasives that remove a lot of metal. I really think you would be a whole lot better off with a media blaster even if you have to rent it.

 

[NasaGT]

yup, those are the ones except I bought the ones for my angle grinder. Those things are great! rust old paint it'll take it off quick.

I agree, these are fantastic for stripping paint and light surface rust with an angle grinder!

Be sure to wear a mask or a respirator, it really throws a fine dust up in the air, you don't want to breath that nasty stuff.

 

[gregski]

Removed Rear Window Molding & Trim

Since there was no glass I removed the rear window molding/trim. It is held in place with three screws on either side, diver / passenger and six trim clips on top. I was able to pull the top trim off by hand. The bottom trim came out easily, in 10 inch strips all broken up.

I learned that the headliner is tucked in under the molding / trim, so it must be installed before a new window goes in. I bet same goes for the windshield.

 

[gregski]

Did almost my entire car with a 19V cordless drill and a few of these. Cuts right down to bare metal without scratching the crap out of it...

Got one, can't wait to try it tomorrow.

 

[RXTbone]

Good luck!

 

[gregski]

Another Day At The Office

So I am getting braver, my abrasives are getting coarser now using 60 grit sandpaper, and added electrical tools, a palm sander, a 1/3 HP hand drill, and a 4 inch angle grinder and even tried some wire wheels since I already owned all these items. Went out and bought a gallon of Klean-Strip Phosphoric Prep & Etch at Home Depot for $14.97 and some Dust Masks for $1.97.

 

[gregski]

The 60 grit sandpaper on the palm sander seems to be working the best so far on the big flat surfaces.

I used the wire brushes and the angle grinder sand discs in the tight spots like the rain gutters above the doors, after removing the chrome trim. When I used the brushes on the flat surface it seemed like it was scratching the metal, maybe exposing prior scratches, I'm not sure.

The 3M Light Rust and Paint Remover disc wasn't worth it, it bends and is probably good for just that light rust removal, LOL.