My radiator core is looking pretty scruffy and before I simply paint it, I've begun to wonder if painting it will affect it's heat transfer efficiency.
Are there types of paint to avoid? As a kid hanging around a radiator shop in the far past, I recall the black paint used was very thin and watery. I can't think what might substitute for that now.
Your local radiator repair shop can recommend the correct paint to be used on a radiator core. It is unique.
Ron the Coilman
Try this link to Eastwood.
Yes it causes engines to run hot, but in some instances when you have lose fins it can help cooling by making a connection between the fin and the tube. I would use a flat black, not a gloss.
Proper radiator paint would be the best thing to use (provided the EPA hasn't ruined it yet).
Otherwise, just cheap flat black primer works pretty well.
Drive carefully, and enjoy, W2
The last radiator repairman within 200 miles just retired this summer.
I remember in the 1960's, restoring a car and the radiator shop gave me some black radiator paint, it was thinned with gasoline! Definitely use correct paint, regular enamel will insulate fins and cooling suffers. Our last radiator shop in town is closed while older owner (one man shop)has knee replaced, we don't expect it to open again, next closest is 60 miles away. Did every radiator shop in the world use the slogan "Good place to take a leak"?
Original radiator paint was pitch based, my old man loved the stuff to fix and fill those little fury leaks in radiators, I'm not up to speed on modern formula, I have a nephew who is still running a rad shop, will ask.
Thin lacquer paint is the ticket, just enough sprayed on to give it the color. A lot of the old radiator shops around here used to use the cheapest black paint they could find thinned to watery consistency with gasoline. KGB
A thin coat of flat black paint will work just fine. No need to get 'to technical' for this.
John is right on the money. The radiator is more a convector than a radiator .
To David Coco: Yes. I may still have a T-shirt with that slogan from a long-closed local radiator shop.
...and I bet every radiator shop thought they were being clever with the slogan. It's interesting that a black painted radiator will actually get rid of more heat than one unpainted, see this basic explanation: http://www.schoolphysics.co.uk/age11-14/Heat%20energy/Transfer%20of%20heat%20ene rgy/text/Heat_radiation/index.html
Really interesting David! So after today's lesson, one could surmise that a shiny car stays warm/hot longer and a car with dull paint would be cooler...?
It's not about shiny versus dull. It's about color. "Black bodies" will transfer heat at a faster rate. In physics and heat transfer textbook problems, they always specify a "black body emitter" as a source of heat.
As for shiny, the link states that since shiny is also reflective, it won't absorb heat as quickly. There is no correlation made as how fast shiny dissipates heat, versus dull.
Actually, I stand a bit corrected. The article does suggest transfer differences in surface finish. I guess it does make sense that surface roughness should play a role. A rougher surface has greater surface area, thus more capacity to cool/heat.
Many years ago I was told by a radiator repairman that the paint they used was porous, for heat transfer.
I also remember reading some where that latex paint is porous whereas oil base paint isn't.
So maybe a thin wash of flat latex is the way to go?