I've been thinking about spray painting the front part of the radiator (as well as the top and sides) with POR 15. Is it possible to restrict airflow by painting the front of the radiator? Anything I should be aware of?

 

Anyone that has a radiator re-cored has picked up a painted radiator, IF the shop takes pride in thier work. the old timer that used to do mine used simple engine paint. "If it works on a hot engine, it will work on a hot radiator" he used to say.

POR15 is used to treat RUST. If you apply it over bare metal or even unrusted metal it will peel off, and you will find you have wasted your $$$. Rust is the KEY to the chemical reaction that makes POR15 as durable as it is.

In a nutshell, use some nice engine paint but to not use so much to fill the tiny voids that may restrict airflow.

John

 

Use radiator paint on the fin section. It's thinner than regular paint and won't affect heat transfer. Eastwood Company used to have it.

POR15 would be a very bad idea on a radiator.

 

I will look for radiator paint. I did not know that there was a paint product specifically for the radiator.

When looking at the POR 15 instructions it stated that the paint could stand temps to 1200 degrees F. and is engine and boiler tolerant - but good to know about it's interaction properties and rust. POR 15 is expensive.

Thanks for your replies and comments.

Dan

 

This would be one of the few places i would not recommend POR15. It is thicker than radiator paint, which is all I would recommend here. The latter would be designed for adhering to the metals and not restricting heat conduction as much.

 

I agree with the others Dan. Definitely do not use POR.

Eastwood still has radiator paint. I used it on my A/C condenser. It's pretty good.

 

Good to hear further confirmations on the radiator paint. I'll be getting it.

Thanks,
Dan

 

I also live in Phoenix, and have used Krylon Semi-Flat black on 100 + radiators on cars I have restored or bought/detailed and sold. It looks great, I always keep 4-5 cans of it around, and have never had an air flow or heating problem using it in this hot climate. Normally I shoot the radiator only from the upper angle, where it will be observed in a show. No need to load up the fins with excess paint. Whenever I have a radiator repaired or re-cored, I tell them NOT to paint it. I do not like that sloppy, wet paint with big drips in it on my radiators.

Joe Varley
AZ
OCA #1448

 

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Thanks Joe for the comments. Krylon paint certainly is a lot cheaper than the direction I went a few days back - went to Space Age Auto Paint in Mesa and got some Black Velvet Engine Paint (a product of POR) - they did not have "Radiator" paint per se. It is also a flat Black paint, very durable and can stand the heat (up to 1200 degrees). They recommended thinning it (if needed) 1 part spirits to 4 parts paint, which I did - and worked well, as this paint is quite thick. I felt that spray paint was too messy (unless the radiator is removed). Black Velvet is an excellent paint, but perhaps a bit of overkill on the price.
Dan

 

I have heard that there is a special radiator paint, and regular paint insulates too much, reducing efficiency of the unit.

 

I think you're correct about that; a good reason to thin the engine paint first.
Thanks,
Dan

 

My rad shop dyes them black. Its not the gloss factory color but it does the job if youre not that picky. Eastwoods Rad paint takes FOREVER to dry. I mean like a week. If your hood insulation hits the radiator like my car, expect to ruin your rad paint job.