Why do some Mopars rust all to hell, and others go for decades with no major issues?

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Salt #1. Getting wet and drying continues the process. Cars underwater take a long time to rust due to lack of oxygen.
 
The first time I noticed the phenomena listed in the thread title was in the mid 1980's.

I noticed that 66/67 B body cars, as well as 70-72 mone carlo and 71/72 torino didn't rust out nearly as bad as 68-70 Mopar B bodies and both earlier and later fomoco and gm intermediates.

I started my Mopar journey as a 66/67 B body guy, so I became intimately familiar with them.
Another thing I noticed was that 2 door cars, if they did rust, rusted bad above the rear wheels.
4 door cars did not.
I learned this is because 2 doors have a direct path from the wiper seal below the rear side window, to the pinch weld of the outer wheel house and quarter panel.
4 doors have the back door, and another layer of sheet metal in the way.
 
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I learned this is because 2 doors have a direct path from the wiper seal below the rear side window, to the pinch weld of the outer wheel house and quarter panel.
67-69 Dart Converts drain any water that gets past the body and the top, INTO the inner quarter by the rear quarter window. It is intended to drain out the body drain holes on the pinch weld under the car.

:rofl:

Interestingly they don't typically rust in that area.
Behind the rear wheel in the lower quarter, yes,
On the front floor pans, yes
 
Don't park your car in a chicken coop
That's funny...

My 67 Dart convert #2 was a chicken coupe according to the guy I got it from. I did find feathers but mostly dirt, 70 lbs so far. Not an exaggeration, I measured it all.
 
67-69 Dart Converts drain any water that gets past the body and the top, INTO the inner quarter by the rear quarter window. It is intended to drain out the body drain holes on the pinch weld under the car.

:rofl:

Interestingly they don't typically rust in that area.
Behind the rear wheel in the lower quarter, yes,
On the front floor pans, yes

Also, it sure doesn't help that the are of the quarter panel as well as the rocker panel where it joins (and the quarter to wheel house area), rarely get any finish coat (think "seal") of paint, just absorbent primer.

That is almost as good as sign that says "rust here".
 
Don't park your car in a chicken coop.
Did someone say chicken coop?

An old friend of mine rescued a '56 Ford sedan delivery that was a chicken coop out in S.D., and he turned it into this:

MX.JPG


Link to a (much shortened) Hot Rod magazine spread that was done on his car: https://www.hotrod.com/features/cruisin-missle-october-1983-982-1232-93-1/
 
To be clear, I'm not talking about your typical rust in a quarter panel or floor. I'm talking rust EVERYWHERE on a car; the rust leaves a car as swiss cheese, where there's not much to work with.

Background: I'm in Missouri. We salt our roads. I know how much rust my cars get every year, but some of my cars...I wonder if they lived in a lead-acid battery plant before I got them. My '75 Valiant is an absolute rust bucket. The tops of the quarter panels have rusted out. The friggin' dashboard rusted out. It seems like it's continued to rust despite being mostly parked for a decade.

My '72 Dart on the other hand, has sat for more time, I've owned (and not maintained) it longer than the Valiant, the top rotted off exposing the unpainted roof to the elements, and it hasn't really rusted much at all through the years.

I have two '92 Dakotas....Same thing; one truck had the frame rust through where the rear cross member bolted up. The upper windshield frame has rusted through in places. It's just RUSTY. The other truck...clean. Nothing more than surface rust, and that's even limited. They've both been in Missouri for the last 25 years.

So, I've heard everything from "thinner sheetmetal after '72 to save weight for fuel economy" to "St. Louis vs. Hamtramck vs. wherever", to "the battery ground is hooked up poorly or wrong so the body is being used like a sacrificial anode". I understand that region plays a huge role, but all of my cars have been in my possession in the same area for 20+ years. I've owned my Dart and Valiant since the mid '90's, and the Valiant floorboard was rusted out even then.

What say you guys? This "Daytona Superbird" is a good example. Even the chrome is rotted off the bumper! The deck lid is roached. It looks like it was driven through a puddle of battery acid. The car has clearly seen a repaint, but WHY is the rust so aggressive on this versus other cars?
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all the Chevrolets I`ve had had rust issues as bad as any thing else !!!
 
I guy could make a living bringing those old rust-free "work trucks" here to the rust belt. Cars too.....
Ya better buy them out of Ok Mo KS Ar, THEY are gold plated in Texas!!!!! (and still rusty!!) You could trade a case of super loud truck mufflers to the locals as a down.... go figure!!! :BangHead: :thumbsup: :confederateflag:
 
The first time I noticed the phenomena listed in the thread title was in the mid 1980's.

I noticed that 66/67 B body cars, as well as 70-72 mone carlo and 71/72 torino didn't rust out nearly as bad as 68-70 Mopar B bodies and both earlier and later fomoco and gm intermediates.

I started my Mopar journey as a 66/67 B body guy, so I became intimately familiar with them.
Another thing I noticed was that 2 door cars, if they did rust, rusted bad above the rear wheels.
4 door cars did not.
I learned this is because 2 doors have a direct path from the wiper seal below the rear side window, to the pinch weld of the outer wheel house and quarter panel.
4 doors have the back door, and another layer of sheet metal in the way.
A lot of truth there. Every model and brand has their rust issues, and not always in the same place!
I agree, the outside of early B does not rust near as bad a outside of 68-79 B. Why>>> Dunno. But if the cowl has rusted and water gets inside the car, then the floors go..on any of them! Like mentioned, did the car sit under a shed most of its life or under a tree..any kind of tree?
I have had many people tell me sitting on grass is the issue. I have had some sit on grass for years, no issue.
Yes, acid rain. Plain rain. Yes humidity. How many cars came to Tx or Az from some years in the rust belt?
I have bought rust free hemi, and 6 pack cars out of Mn. with NO rust because they were considered special and never driven on salt!
I bought a 70 Charger RT about 2000 that sat on the dirt in a budy's small private boneyard on its floor for years, NO suspension and when we pulled it up and put it on my trailer, the floors were perfect! WHY? The cowl was solid, windows had always been UP, the weatherstrip was still sealing, sat under NO trees, and they oiled the dirt down every year with used oil NO weeds!!!!!

I have a bud that owned a hemi 67 GTX since the 80s. Rrural N. Mo. It never sat under a roof , he hid it in the woods on his brothers farm, etc. Solid old car that had not been on the road since the 80s. Then in the late 90s he did a complete resto, body/paint, interior, new bumpers, etc. Great job. The it sat in his enclose pole barn "garage", on limestone gravel for about 3-4 year UNDER a store bought car cover of some brand, and when he uncovered it the first time in 4 years, the new bumpers had rusted bad , the paint looked like crap, the interior was full of mold, and rat pee, you get the idea.
 
That's funny...

My 67 Dart convert #2 was a chicken coupe according to the guy I got it from. I did find feathers but mostly dirt, 70 lbs so far. Not an exaggeration, I measured it all.
I don't think that was dirt, man...
 
One thing I see people not realizing, many of these old cars had the body/paint done to some extent back in the 890s,90s. Several decades later, most do not always look like they had such done. Most times these were RoadRunners and 70-1 E bodies, and such, and not necessarily A bodies of any flavor.

Just like Texas, East side of state, like East of I35 it is humid and more rain, than the much drier West of !35. Makes a difference. Go further West and it is dry!!!!!

I remember years ago, I bought a 70 Duster off a hobbiest in S Az. I bought it over the phone, before internet and I could sum up the honesty of a guy with an actual phone call. We got to talking AAR and TAs as I had a passion for them back then. We got to talking rust in various models of Mopars like in this thread. He mentioned the fact that yes, Az, is HOT and DRY, but it does rain in Az. and the darn trunk always leaks and thus can rust at least somewhat!

I lived in Mo. 37-8 years from 1979 to 2017. Ga, till 1979. Born in '48. Yea I am that old.

I have a Pontiac bud back in Mo. he has several GTOs, etc. he has had for decades. His trunk floors NEVER rust, he keeps them coated with used ATF! His cars have the "real car" aroma!! :BangHead: :rofl:
 
I don't think that was dirt, man...
LOL!

It was the finest red clay Colorado and/or Texas dirt. it got into every nook and cranny. if air could get in, its in there.

The car sat in a field or two since 1976
 
People do not believe me when I say, these old non rust belt cars mostly rust from the insides.
If they sit out in the weather with the windows rolled up, water gets inside past those old seals, but can't get back out. Moisture is a rust magnet, even without salt.

My Dad had a 62 Polara 500 convertible he bought new, was always in a garage or carport until the mid-70s when he got the bright idea to park it outside and put his lawn mowers in the carport. By this time I was no longer living at home, but during a visit I went out to the convert and opened the doors. There was 2-3 inches of water just standing in the floorboards. It didn't take but just a year or two for the floors to get rust holes in them.

He also parked his 67 Hemi Charger outside, but somehow it avoided getting rusty floors. It's mine now, and has been garaged for the last 40 years. One of the most solid cars I've ever owned. Only rust ever was the lip under the rear of the trunk, I think from where the trunk medallion leaked.

Go figure.
 
Oh, and the chicken coop thing? I bought a bunch of parts from a 1956 Studebaker Golden Hawk that had been stored in a chicken coop for several years. Seller had tried to sell the whole car, but when someone was gonna buy it, the frame broke in half while loading it on the trailer. So that deal was off. Instead, the seller parted it out. Had good stainless steel trim, fiberglass fins, engine and trans, but not much else. Chicken poop is VERY corrosive.
 
I guy could make a living bringing those old rust-free "work trucks" here to the rust belt. Cars too.....
When i was stationed I Sacramento CA a long time ago, I knew a guy who bought up rust free California cars and trucks and shipped them up to a business up north (Michigan I think). He made a very good living doing that.
 
When i was stationed I Sacramento CA a long time ago, I knew a guy who bought up rust free California cars and trucks and shipped them up to a business up north (Michigan I think). He made a very good living doing that.
Back in the late 80s, early 90s. (before the first Mopar price bust,) there were some guys in Mn. that did that. They did well. The first bust was in 1990. But it took another year before the word really got out, and the high end "investors" folded and stated to pull out. Pull out meant them selling their high $ hemi E body to another high $$ buddy with the cash, to save their ***.
What was funny was how Mopar Action every month kept mentioning another high $ sale of another 70-1 hemi Cuda. How did the not know!?????
Players (high $ players) I call them.
 
Pulled an old 60 Imperial out of a cow barn. Was in there approx 15yrs on concrete. Looked good outside but the bottom was cheese. Cow pee not good
 
A friend had bought a 71 Cuda that lived in Hawaii its whole life, not a bit of rust (heater delete car too). I was surprised about no rust. He said it was from one side of the island (can’t remember which) on the other side ALL cars rust away in short time. Something about the winds and rain from that side that the mountains stop from getting to the good side. Probally what the one said of the coastal salt rain.
 
A lot of truth there. Every model and brand has their rust issues, and not always in the same place!
I agree, the outside of early B does not rust near as bad a outside of 68-79 B. Why>>> Dunno. But if the cowl has rusted and water gets inside the car, then the floors go..on any of them! Like mentioned, did the car sit under a shed most of its life or under a tree..any kind of tree?
I have had many people tell me sitting on grass is the issue. I have had some sit on grass for years, no issue.
Yes, acid rain. Plain rain. Yes humidity. How many cars came to Tx or Az from some years in the rust belt?
I have bought rust free hemi, and 6 pack cars out of Mn. with NO rust because they were considered special and never driven on salt!
I bought a 70 Charger RT about 2000 that sat on the dirt in a budy's small private boneyard on its floor for years, NO suspension and when we pulled it up and put it on my trailer, the floors were perfect! WHY? The cowl was solid, windows had always been UP, the weatherstrip was still sealing, sat under NO trees, and they oiled the dirt down every year with used oil NO weeds!!!!!

I have a bud that owned a hemi 67 GTX since the 80s. Rrural N. Mo. It never sat under a roof , he hid it in the woods on his brothers farm, etc. Solid old car that had not been on the road since the 80s. Then in the late 90s he did a complete resto, body/paint, interior, new bumpers, etc. Great job. The it sat in his enclose pole barn "garage", on limestone gravel for about 3-4 year UNDER a store bought car cover of some brand, and when he uncovered it the first time in 4 years, the new bumpers had rusted bad , the paint looked like crap, the interior was full of mold, and rat pee, you get the idea.
My 66 Belvedere sat in a cow barn for a very long time, it had light surface rust all on top sides, nothing under or inside of car, even quarters are rust free. Cowl was bad because of a rats nest using headliner material. Replaced that from a doner car

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My 66 Belvedere sat in a cow barn for a very long time, it had light surface rust all on top sides, nothing under or inside of car, even quarters are rust free. Cowl was bad because of a rats nest using headliner material. Replaced that from a doner car

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66-7 B bodies did not tend to rust near as bad a 68-70 B bodies., in general. Much better sheetmetal. But funny as they never bring the $$$ of a 68-70.
If leaves and crap gets into the cowl, they all rust there.
 
Northern cars rust from the bottom from salty roads southern cars from the top from salty ocean also 100 thousand miles is high miles on a northern car a n 200 on a southern car
 
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