Radiator fin rust
 

I am having problems with rust appearing on the fins of my relatively new 30 Coupe radiator. I honestly don't know where it came from -- possibly overflow from radiator cap. How do you clean the rust without damaging the radiator, and then what is the best way to keep it clean?

Re: Radiator fin rust
 

I got a spray cleaner specifically made for rust removal on radiator fins from O’Reilley’s. Spray on, brush gently, rinse off. Try your local auto parts store. Flush your radiator/cooling system too and add some rust preventative to your coolant. Soluable oil works well.

Re: Radiator fin rust
 

Thanks. Do you remember what the rust removal cleaner was called? I looked on the o'Reilly website but did not find it.

Re: Radiator fin rust
 

Was it called Metal Blast? I see that on Amazon.

Re: Radiator fin rust
 

Once you get it clean, there is radiator paint. Its not regular spray paint.

Re: Radiator fin rust
 

This is something that won’t help you but I thought it was a funny gimmick.
https://jalopnik.com/how-volvo-once-...mov-1831438959

Re: Radiator fin rust
 

Are you certain it is rust forming? Typically the fins are made of brass or copper alloy. To my knowledge, those don't rust.

As far as cleaning it, I would probably start over and use EZ-Off oven cleaner to remove anything organic from the fins and tubes. This will include the paint which should take it down to the bare fins/tubes. If there is rust remaining, I would use either a Rust Mort or Rust911 product to remove that. Then use a Black lacquer to repaint the fins. A thin coating of paint is all that is necessary to prevent the alloy from corroding. Too much paint will act as an insulator, so just enough to get coverage is all that is necessary.

Re: Radiator fin rust
 

It is possible that the rust on the fins is from a small leak in the core that is letting rusty water from inside the radiator / engine block because antifreeze is NOT being used.

Even though the radiator is new they CAN have leaks due to defects or leaks from radiator cap.

Water in a radiator is the first to freeze long before the water in the engine block freezes.

Even though the radiator is new they CAN have leaks due to water freezing in the radiator core if antifreeze in not being used.

Re: Radiator fin rust
 

If the coolant is rusty, that is a problem. Clean it out well and put in antifreeze or another rust preventing coolant. You DON'T need rust on the inside any more than on the outside.

Re: Radiator fin rust
 

Hello all,

New member here.


Looking forward to learning a lot from you all.

Re: Radiator fin rust
 

Thanks. Is there a rust cleaning solution that should be used to clean out the radiator before re-filling?