Painting an Aluminum Radiator

[Green hornet]

I purchased an aluminum radiator that has factory looking tanks. I want to paint the tanks, not the core so that it retains the stock look. Any issues with this idea. Any suggestions on type of paint / primer. I would prefer a rattle can product because of simplicity.

 

[gammamaniac]

https://www.eastwood.com/ew-radiator-black-12oz-satin-finish.html

 

[70-camaro]

Before you use the radiator black wipe the tanks down with wax and grease remover. After that I sprayed on Bulldog adhesion promoter then painted. Has been on mine for about 2000 miles with no issues. I bought my Bulldog at the local auto paint shop.
https://shop.advanceautoparts.com/p...gclsrc=aw.ds&dclid=CMiI-9Lik94CFUfYwAodLj8BxA

 

[mark wagner]

for aluminum you should use an etching primer followed by the paint. do not use epoxy over the etch primer, it will peel off in short order. Bulldog is for plastic bumpers BTW.

 

[70lt1z28]

When I was into restoring C3 Corvette's, many of the external parts such as the wiper door and headlights were aluminum. The accepted best practice at the time to prep them for painting was to Alodine coat them. I never had a paint adhesion problem after doing this.

https://www.amazon.com/Henkel-Alodine-Metals-Conversion-Coating/dp/B00NIZHYJY

 

[Green hornet]

I ended up using engine paint from Duplicolor. No primer needed. I scuffed it a little and cleaned it with lacquer thinner. Coated it with low gloss black. It turned out nice and is holding up well.

 

[CAMeeks]

for aluminum you should use an etching primer followed by the paint. do not use epoxy over the etch primer, it will peel off in short order. Bulldog is for plastic bumpers BTW.

Bulldog® Adhesion Promoter is designed to promote paint adhesion to all automotive surfaces, even problem plastics. It works equally well on all flexible or rigid plastics, fiberglass, aluminum, glass, chrome, vinyl, galvanized metal, and painted surfaces. Bulldog acts as a tie coat by allowing several different surfaces to be painted at the same time to assure a smooth, flawless, durable finish every time.

Seems to cover more then plastic.

 

[Jeep43]

I would try to use as little paint as possible as to not insulate the fins from the air.

 

[70-camaro]

I used tape and paper and didn’t paint my fins.

 

[70lt1z28]

I would try to use as little paint as possible as to not insulate the fins from the air.

This actually gets very technical while as you say the paint can act as an insulator (impedes heat transfer) , but black also enhances emissivity:
Emissivity is a measure of the efficiency in which a surface emits thermal energy.

https://en.wikipedia.org/wiki/Emissivity
https://www.thermoworks.com/emissivity_table

Generally, a thin coating of black on a radiator enhances its ability to move thermal energy from the inside to the ambient air. They didn't paint the radiators from the factory black without good reason.