This is the second radiator in a number of years that seems to be disintegrating from the outside.
The thin cooling fins between the actual ribs are disintegrating, and turning into a copper-dust/powder.

Car is a daily driven 1973 Dodge Dart.

It's clear some kind of galvanic corrosion is happening here but I'm wondering why because it can't be an 'isolated issue'?

I try to save the radiator and apply a coat of satin black paint on it occassionally, but ofcourse this might slow it down but doesn't seem to stop it.

Out on a limb here but could it be electroyalisis (sp)? Someone said once about with your meter on low volt scale, one probe in the coolant & the other touching the radiator metal & over a certain # of tenths of a volt being generated that there is some galvanic action takeing place (like a battery that is causing corrosion/rusting).

That'd be my first guess also. Read this: https://www.hotrod.com/articles/keep-your-cool-preventing-radiator-eating-electrolysis/

Do you live by a nuke plant or a military shoot to kill trespass base?

Does your pee glow?

Not more than usual...

I do wonder if the occassional road salt will speed-up the process at hand here.
We've had a very mild winter here uptill now with only one-or-two road salt applications.

As for the electrolysis, I understand, but wouldn't that be happening on the inside of the cooling system where the coolant actually touches the copper (and iron and aluminium).

I could try and stick a voltgauge on various places in/on the cooling system to find voltage-differences.

I've also been thinking of insulating the radiator from the frame it's mounted to. But then again, millions of cars have been made this way. If there was a problem it would have become apparent very quickly I think.

Maybe think about a sacrificial anode (zinc?) solution?

How old is it? I've seen lots of them do it after they get some age on them. A touch of salt and water, and copper that thin will eventually go poof and disappear.

Kevin

Well, I had the idea of coating the radiator with a zinc-primer.

I wonder how an anode will help when it's mounted on the inside of the radiator while the outside is deteriorating.

My thinking is the current is now flowing to an unknown cathode agent outside the rad, thru the uncoated inner metal, an interior immersed anode would reverse that current flow direction, or at least reduce it.

my opinion after 37 years of radiator repair,its salt!!,do you live near the ocean by chance??

He lives in the Netherlands, you know where the little Dutch boy put his finger in the dyke to keep the ocean from flooding the countryside. Yeah, he lives by the ocean.

I too thought of salt or other road de-icing materials. But I assume the problem would be widespread in the OP's region, and therefore he would know the cause. I could be wrong...

Yes I live near the westcoast of the Netherlands. Some 10 miles from the coast.

Road salt is also used vigorously here whenever freezing night time temps are expected.
I think we've had a just very little frost till now but I know the roads have been 'serviced with salt' a few times already.

I tend to believe the road-salt could be a major cause of this issue, even though I don't recall other cars having these issues.

Maybe when the original black paint on the radiator gets to wear 'thin' enough, the salty moisture kicked up by cars driving in front, can do it's thing on the copper better and dissolve it.


I can even see a copper build-up on the dirt on the engine.
Since this is a fresh engine install (few months ago) and I only noticed the copper 'dusting' on the block fairly recently, I also tend to believe the issue mainly happens during the colder months.

I would say its salt...

I've got a couple radiators here that have that same problem. Most of these radiators are from the 80s, either replacements of from cars that have seen several winters in this area. Seems the newer replacement radiators have this problem show up a lot quicker then it did with the old original radiators. Gene

I have a radiator doing that in a car that came from Nevada with absolutely no rust underneath (and I assume no exposure to salt and very little to rain).

We have seen some trucks that were like that where the rad was like paper. If you touch it you were afraid of popping a tube. Those were almost invariably trucks run in areas with high levels of highway salting or trucks run on the coast.

I wonder in your case if it could be a caustic agent (alkali) at work, lime dust, etc

Freezing nighttime temps have arrived here in my country and the roads are already turning white, from the salt!

I took some pre-emptive measurements and sprayed a layer of zinc-primer on the front of the radiator. Hope it stays together this winter...

I sometimes think the roads are slippier because of all the salt they dump on them than from some possible frost that might appear on the surface...

I was a radiator guy too. I would say salt is culprit here...that is not similar to the electrolysis I’ve seen. That (electrolysis) usually shows up as black specks on the tubes themselves.

Do you daily drive that Dart in the snow? If you do, you are a brave man. I remember driving my /6 Dart to highschool a few times in snow. This was a long time ago, unlike now with the plethora of snow days It was an adrenaline raising experience.

I daily drive the car year round. Snow or shine!
It's my only means of transportation, besides the 'older' cars I have, which function as backups if the Dart needs to spend time in the garage.

We don't really have much winter snow overhere usually, at least not in my part of the country.
There is however some snow forecast for tuesday.

This was back in 2012, which was a colder winter for us.
Sure had some fun in that white mess...

I'm impressed.