Bought a partially finished 28 Ford Roadster project. Has nice shinny new aluminum radiator. Looks too shinny and nice for rest of car. Can I paint it black and still get good cooling for a mostly stock (300 hp} 302 Ford V8? Plan to use a 4 blade stock Ford fan off a mid 60's mustang motor. Thanks
Most radiator shops I have experienced put a coat of black paint on them when they are done. So my guess it would be just fine. I painted the stock one in my driver with just **** rattle can paint years ago and never had a problem. If you aren't having heating problems now, I doubt it will make that much difference.
For a stock appearance I used Eastwood's black radiator paint for a 1969 Ford Torino restoration. No joke, 10 years later it still looks almost new. I have also had radiator shops paint my radiators, always bad luck.
A coat of paint is just like a coat of insulation. The heat has to soak through it to get to the outside air to transfer. The best way, if you must apply a color is use spray canned black barbeque paint (most hardware stores stock it). Use light fog coats until you get even coverage and stop. The initial fireup will cure the paint bonding it to the core materiel. Frank
Yes, the heat has to get through the paint to get to the air, but my guess is it doesn't insulate all that much if anything really. If paint was such a good insulator, don't you think we would be using to do just that. When was the last time anyone suggested adding another layer of paint to your house will help insulate it? Touch an unpainted radiator and a painted one and let me know which one you think is hotter. The heat can't just stay in the radiator and build up to infinity, it has to go somewhere and my guess is a thin coat or 2 of normal paint isn't going to do that much to stop it. Maybe, it might bump the operating temp up a degree or 2, but I doubt it suddenly jump anything noticeable. They do make special paints that do help heat transfer. I know on some light fixture applications for instance, some manufacturers said they use special coating to help the heat radiate better - special ceramics, nano-tech, etc. But, I never heard any suggest they used paint to insulate anything. And believe it or not, a lot of challenges with light fixtures is in dealing with the unwanted heat, not with the light. The light is the easy part. Now, as to it sticking or not, that is a painting prep issue. I didn't do hardly any prep. on my old stock radiator because it wasn't worth the effort and just used OSH brand satin black rattle can paint on top of whatever was already there. It has only flaked off some around the filler after almost 5 years now.
Yes, a very thick layer of paint or powder coat all the way through the core would not be good. But a thin mist of mat black just on the front and the tanks will make it look a lot better, and will make no measurable difference to heat transfer.
I am not a painter but have had several radiators of all types painted with Base coat/Clear coat automotive paint without any problems. People paint there engines wiith this type of paint all of the time and they do not run any hotter. where are the mythbusters ????
Good answers so far.. I have a Griffin radiator on my T that just looks wrong against the chrome radiator shell. I don't mind the tanks being bare (I have polished them) but the fins... look like ****. I can't get the temp to go over 180 where I live, so maybe some Eastwood radiator paint, or some barbecue black, fogged on in a few different coats/applications will be okay?
The Italian engineers researched heat disipation colors for their motorcycles way back in the 40's and found that flat black got rid of heat best. Guess what, pot belly stoves were flat black as soon as they were invented because they knew that flat black gives off the heat
(edit)Good or Bad? Neither, it's a happenstance choice. It's a radiator for cri'ssakes. I don't paint mine. Clean with muratic acid before soldering then use it. If a car overheats with a painted radiator, taking the paint off probably won't help much. I'd consider the other more tangible remedies; fan size, fan clearance/position, shroud, etc.
I had my aluminum radiator powder coated black...works just great, looks good too. Aluminum radiators in customs or rods look wrong in my eyes. Mine is a PRC and they said it would be fine also,
Matte black has been known to aid heat dissipation. One of the reasons, why the SR-71 Blackbird was painted matte black!
I'd paint it for no other reason than to keep the corosion from the elements from working on the metal. Unless it's made of a marine alloy of aluminum. In that case I'd paint it anyway.
Go on ahead and paint the radiator. The heat transfer loss due to paint being on a radiator is less than 1%. So is it going to make a difference? You wouldn't even notice it. If it did stop significant heat transfer don't you thnk that the big 3 would leave them bare aluminum?
juwst make swure that you sacuff it really good with a scotch brite pad and use mtal prep on it and alot of light coats till its covered good luck bro!
so just because its a radiator it has to look like ****? Paint it, it'll be fine. I powder coat the tanks and paint the cores, never had any heating issues. EVER. Even with AC.
[ quote 29nash; I don't paint mine. Clean with muratic acid before soldering then use it. It's a radiator for cri'ssakes. If a car overheats with a painted radiator, taking the paint off probably won't help much. I'd consider the other more tangible remedies; fan size, fan clearance/position, shroud, etc.;quote 29nash] "has to look like ****"??? Quite a conclusion yer' jumpin' to there. There are tons of unpainted radiators that look *****in', includin' mine. .
Not true. It really was because "Black bird sounds better than like SR-71 Green Bird or SR-71 Red Bird or SR-71 Puce Bird. Duh !
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