"painted" coolers, radiators, etc

[Johnny248]

Sometimes you will radiators, transmission coolers, oil coolers, p/s coolers that will be "painted" black from the factory while other times they will be bare (maybe clear anodized?) aluminum. Does one do a better job cooling than the other? Does this black have an effect on the cooling efeciency of the fins? One vehcile own has a bare transmission cooler, while another is black. I've seen aftermarket universal offer both styles also. I would assume that it is different than say spray painting yours black, which my guess would hurt cooling performance by having a layer of paint over it?

*These are just generic pictures of the finish. Not the same size/model

 

[thescreensavers]

Yes the paint is going to hurt cooling a small amount, but will likely look better behind the grill or bumper.

 

[50yr Street Mech]

Living in the rust belt, painting is almost a must. Doesn't seem to affect cooling whatsoever, and radiator life doubles.

 

[Johnny248]

Living in the rust belt, painting is almost a must. Doesn't seem to affect cooling whatsoever, and radiator life doubles.

Think BBQ paint or engine paint would be the best option?

 

[Jetronic]

Think BBQ paint or engine paint would be the best option?

radiator paint

 

[oil pan 4]

Yes the paint is going to hurt cooling a small amount, but will likely look better behind the grill or bumper.

Depends.
Shinny metal has lower emissivity.
Painted metal may exchange heat to air slower.
My own experiments show a light collating of black paint aids heat rejection, as long as you can keep the item painted out of direct sunlight.

 

[Johnny248]

Depends.
Shinny metal has lower emissivity.
Painted metal may exchange heat to air slower.
My own experiments show a light collating of black paint aids heat rejection, as long as you can keep the item painted out of direct sunlight.

When I was younger, I was working for an audio company. They were engineering an amplifier where we had to machine the heat sinks and then sent them out for black anodizing. When I asked about the black, one of the engineers told me that black radiates or dissipates heat better. If that is true, I have no idea.

 

[kschachn]

When I was younger, I was working for an audio company. They were engineering an amplifier where we had to machine the heat sinks and then sent them out for black anodizing. When I asked about the black, one of the engineers told me that black radiates or dissipates heat better. If that is true, I have no idea.

Yes a black body is best for radiating heat. However, an automobile "radiator" transfers heat primarily through convection. Some paint to protect the aluminum is beneficial in that regard but it should not be too thick.

 

[50yr Street Mech]

I put a coating of high heat paint on the condenser and radiator, ( if the radiator is out of the car ). This way I can hit both sides. That salt just eats everything. Before you know it, nothing left but the rails. Terrible stuff. Paint works well. 2 thin coats and that's it. Whatever I have in the garage. Be it gloss or flat black. Better than nothing.

 

[kschachn]

I put a coating of high heat paint on the condenser and radiator, ( if the radiator is out of the car ). This way I can hit both sides. That salt just eats everything. Before you know it, nothing left but the rails. Terrible stuff. Paint works well. 2 thin coats and that's it. Whatever I have in the garage. Be it gloss or flat black. Better than nothing.

The condenser I replaced on my old ECHO was just that on the bottom 1/3. It wasn’t leaking but I figured it was just a matter of time.

 

[tcp71]

Black have greater emissivity in radiating thermal energy. Black surfaces absorb more radiation and therefor emit more as well. The effect is minor however compared to surface area and especially airflow.

 

[50yr Street Mech]

No vehicle can survive " THE SALT BELT" without keeping an annual eye on corrosion. Will be moving out of the belt in 7-8 yrs. Currently, all my vehicles have been sanded and re-painted / undercoated. Just need to monitor them now and do some touch up work here and there.

 

[Johnny248]

No vehicle can survive " THE SALT BELT" without keeping an annual eye on corrosion. Will be moving out of the belt in 7-8 yrs. Currently, all my vehicles have been sanded and re-painted / undercoated. Just need to monitor them now and do some touch up work here and there.

What do you use for undercoating?

 

[50yr Street Mech]

First I sand and clean, then paint with chassis paint, then just use any Undercoating in a spray can. I stay away from the rubberized stuff. Heard it traps moisture in between the coating and the frame. So I go with 3M, or whatever else I can find that's not rubberized. What a mess. Rollin around under the car. Overspray all over the place. But, it's worth the aggravation. The main thing is the prep. You don't prep well, nothing will stick. Sometimes it takes me weeks to do one car. Sand, clean, paint, let paint cure, then undercoat, then clean all the overspray off the car's paint. Real PITA !!!!!

 

[oil pan 4]

When I was younger, I was working for an audio company. They were engineering an amplifier where we had to machine the heat sinks and then sent them out for black anodizing. When I asked about the black, one of the engineers told me that black radiates or dissipates heat better. If that is true, I have no idea.

Yes it absolutely is true. Scientists have been studying this phenomena for around 170 years, maybe longer.

 

[GR_CoB]

YEARS AGO Mighty Car Mods channel on YouTube did a test. Against most logic the black painted intercooler did better than not painted one.