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Pitted roof 71 Charger

rocky61201

Well-Known Member
Local time
2:15 AM
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Location
Camp Pendleton, CA
I've been dreading getting to work on the roof and now I know why. Car originally had canopy top vinyl roof and somebody decided to take it off for whatever reason and slap some putty over the pitts and prime it up. Just wondering what your recommendations are since new roof skins and chrome vinyl roof trim along with drip rail trim is extremely hard to come by.

Once I get rid of as much rust as I can and smooth the pitts out as best I can, is it safe to put some type of rust preventing coating over it and then spray some good quality (PPG) expoxy sealer primer over it. Then continue on with smoothing it (glazing putty) out for final paint?

Am I on the right track or does anybody have a better recommendation?

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suggestions in no particular order, new roof, donor roof, talk to Donny.
 
Another rust-free Calif car , huh ?

My '72 Coronet's roof is also a victim of a vinyl top and the resultant pitting ... and outright rust holes .

I've actually brazed some of the pits , after using a wirewheel and spray-on rust converter / inhibitor , then priming the **** out of the areas with zinc-rich rattle can primer .

Your pics just go to show that Ca cars aren't free of rust ! They just rust in different areas ( from the top-down in most cases ) .

How's the rest of your '71 look ?
 
Gonna be a challenge for sure given that what you say (I have no idea on 71s) that roof skins are not available. Try to get it media blasted; soft delicate media with a little 'etch' to it to dig out the rust, you're still going to have pits after media blasting, and they will be bigger pits -- even holes if the rot rotted thru the metal which will require you patching it up. But, after it's blasted you know where you are, and which way to go. You're going to need to fill the panel, I'm not a painter, I'm sure there are other more qualified folks here that paint and can tell you which way they would go if it was their car/project. Good luck!
 
Thanks for the advice guys, much appreciated. Called AMD today and they said no roof skins and nothing new on the horizon other than what they already sell on their website for us 3rd Gen guys. Oh well.

Cornet - Your right the rest of the car is perfect and free of rust. Floor boards, trunk, ect. Just have a lot of hammer and dolly work ahead of me because of 39 years of minor fender benders and the cheap insurance body work jobs to follow. You know, caking on putty to make the rest of the contour match the high spot from a dent puller gone too far, and just plain lack of proper hammer and dolly work. Some spots had 3/4 to and inch deep of bondo. lol
 
We all have opions, they are like...

Anyway, assuming a donor skin is not possible and you have to save what you got, here is what I would do.

Plastic bead blast by a pro who won't overdo it. This will get rid of lots of issues, but not the rust.

Next, stripper discs, lots of them, on a 4-1/2 angle grinder. Slowly work the pits without heating the metal. This will be time consuming, but it should leave an 80 grit brush finish on bare metal.

Next, Rust converter from Eastwood. I have used this and it is awesome. This will stop the rust in its tracks. I recommend the aerosol over the bulk, its just so easy to apply. Let cure 2 days.

Next, epoxy primer. A good quality anti-corrosion type. Usually a primer sealer. Same brand as whatever you will topcoat with. Some people swear by one or the other, personally, I have not seen any real difference as long as you stay within brands.

Next, a sprayable polyester filler high-build primer. 3-5 coats per instructions (more if the pits are real deep). this stuff will build and level the pits very well. Get a good night or two rest cuz the next few days will suck....

Block sand, the surface to level it and fix any imperfections to whatever your definition of "perfect" is. Hot tubs work well to fix those aching muscles.

lastly, final prime before paint. Don't try to paint on the polyester filler, that stuff is like a sponge and you will waste/need a lot of paint.

That is just what I would do. Some people call me crazy. My wife is their cheerleader.

Randy
 
If you use the sanding discs; it will add time, and take metal away, good metal before you get to the bad metal which is in the pits. I still stand by my recommendations, should not be more than 1 hr of work for the media blaster guy.
 
More awesome advice, thanks again. Hopefully this weekend I can get around to removing the rest of the primer/putty that is hiding the rust pitts and decide on a final course of action.

The car is torn down and ain't moving out of the garage any time soon, so paying a professional blaster to come to my house will affect my decision. I ain't forking over the cash for proper blasting equipment that won't get used enough to justify the cost.
 
If you use the sanding discs; it will add time, and take metal away, good metal before you get to the bad metal which is in the pits. I still stand by my recommendations, should not be more than 1 hr of work for the media blaster guy.

I am with you Donny, but there is a high chance the "pro" he gets won't balance the soft-media grit-media right and end up making it worse. There aren't too many pros out there who know what they are doing.

As for the discs, I did not say sanding discs, I said stripper discs. They do not take much metal away but are good for the surface imperfections.

I use these:

http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

They are from Home depot. if the link does not work, it is a Norton Rapid Strip disc that screws right on the 4-1/2" angle grinder. i also get them online for a cheaper price if I am not in a hurry.

Randy
 
My roof was badly surface rusted, and flaking, but not pitted.

The wheel that RGAZ describes is the only thing that worked for me.

I went through 4 full packs of 80 grit and didn't get a square inch down to smooth shiny metal before I tried one of those. I got one from a harbor frieght style tool store and another from Lowes. IIRC, the Lowes one was noticeably better, but both were better than the sander, wire brush or flap wheel.

I spent 2 hours per night on that roof, or until I couldn't hold the drill any more.
I marked out roughtly 1/8 of the roof, and brushed and primered each 1/8 at a time, then I'd go back the next night and start on the next section, digging towards the section from the night before, untill I hit the good metal..

Seemed like it took forever, 2 hours at a time.
 
Goodness gracious, that's a huge expenditure of time my friend! The only blaster that will come to you house will be a Soda blaster, or, sand blaster; both are expendable and unrecoverable. Soda is not good with rust, Sand is, but there are draw backs to that too. Good luck! Can you take it to your local blaster? Try googling Plastic Media Blasting in your area, you may get lucky! Good luck!
 
Seemed like it took forever, 2 hours at a time.

Its a labor of love. I did the same thing with my hood, both sides (after removing the webbing). It took a full day and three stripper discs but it is pure bare metal now, no rust at all. total cost, $27 and about 5 hours.

I'm telling you, if you can't get a good media blaster to come over, just give the stripper disc a try, they are only $9. It might suprise you.

Randy
 
If you use the sanding discs; it will add time, and take metal away, good metal before you get to the bad metal which is in the pits. I still stand by my recommendations, should not be more than 1 hr of work for the media blaster guy.

Donny's correct, and in the long run cheaper than wasting your time with expensive stripping disc's. I believe you will have a little swiss cheese after blasting...some fabrication will be in order if you cannot find a donor roof...
 
Just a thought from the FNG but has anyone thought about the old standby " Naval Jelly " which would be inexpensive and follow that with a thorough area cleaning and prime.
 
Tried the stripper discs you gave me the link too, and it worked just OK. Really had a hard time with it gumming up with filler and primer the previous owner laid down. I don't think the bondo was completly cured or maybe the combination of rust underneath along with a little moisture and you get the picture.

Once it gums up it was hard to keep secured on the angle grinder, it kept sticking in place. Seems a wire wheel on a chrafstman drill works pretty good and my compressor isn't constantly running.

I though about naval jelly or some other chemical remover but car is in garage with steep uphill drive way. I really wouldn't have a good way to give it a good cleaning once I'm done with that cuz I can't roll it out of the garage and then back in. Last time I rolled it out it took 5 guys to push back in.

Again, thanks for all of the advice and I'll post some pics when I'm done.
 
Why Naval Jelly and other methods when for about one hr of work, the media blaster can get it done perfectly and minimal mess.
 
I used the wheels in a drill. That seemed to work better than my air tools for this purpose.

There are no blasters in my entire county, and the only ones listed in the phonebook/web in a three county radius are sand only industrial outfits.

I am 1/2 tempted to start up my own Donny style franchise around here.

There are quite a few motorcycle shops and auto restorers around here. I wonder what they do. Could they all have their own equipment?
 
Good! Go for it! Nope, they all don't have their own blasting equipment, I am sure of that! Too expensive to buy/run/maintain.
 
Here I go hijacking a thread again...but at least it's relevant...

Donny, would you mind sharing what type of compressor you are using for your blasting setup? What is the key spec? CFM?

I've seen HP, PSI, CFM, Gal, and CFM@PSI ratings. Hard to find all listed for a given model.

Where's my pirate smiley??

I think I may have found a cadidtae that is 18HP, 150PSI and 18CFM. Is that enough?
That's more HP than my riding mower:)

Does tank caopacity matter?

What about a gas engine?

Thanks.
 
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