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MG TD TF 1500 - Best paint for Radiator?

I just got the radiator out of the shop with new core.

I had them leave it unpainted. What is the collective thinking as to the least heat restrictive paint.

In the past I have used Industrial Rusteoleum spray can.

Have you found anything better?

Thanks,

Sherwood
S Parker

I just paint with any good quality semi gloss black paint.

The radiator doesn't get very hot so what was wrong with the Rustoleum?
Willem van der Veer

I paint the finned area with a very light coat of BBQ flat black paint. The tank ends with a good coat of Gloss (keeps clean better- which dulls to semi-gloss). I am sure you will get lots of advice on this topic. The important thing would to put as little paint that you get away with on the finned area so as not to impede heat transfer.
...CR
C.R. Tyrell

Nothing wrong with Rustoleum but at this opportunity I thought I would ask if there is something better. The goal is not to inhibit heat transfer.

The flat black bbq paint seems to have merit.

Sherwood
S Parker

CR has the right technique. Any flat high heat paint (exhaust) will work too on the heat exchanger fins. Gloss for the rest.
Christopher Couper

And Eastwood make a rattle can black paint specifically for radiators but not sure how this differs from ordinary black rattle can paint.
John Quilter (TD8986)

Fewer solids for less build up with the radiator paint . Regards, tom
tm peterson

Gents,

It would take a precision laboratory to detect the difference (if any) between one black and an other. The problem with T series cooling is almost always crud in the radiator or engine water jacket.


Regards,


Jim Haskins 1953 TD
J. M. Haskins

I'm with you CR! Show off your real metal! Screw the idea cheap black paint is the way to go. It is the easy way.

Show some good old fashioned shiny brass. I just spotted one of my old radiators on the shelf smiling back in its gold shine. Last radiator I had recored, I told them not to hit it with paint. I buffed out the brass tank on top and shot it with clear coat. Let that silver colored solder glisten in contrast. This is an old, classic car with classic metals! Ever try to shine plastic?

I did shoot the fins with just a hint of flat black on about a 45 degree angle so the outsides look black and really accent the brass, but too much paint cuts down on heat transfer. The light black contrasted with copper core gives a sort of aerodescent appearance.

This is just my opinion. I don't do collective thinking with a one track mind. Do what makes you happy!

Enjoy!
JRN JIM

And why would you worry about rust in Arizona in the first place? ;-)
Rgds Mike
Mike Fritsch

I painted the original Harrison radiator in my '54 Chevy pickup three years ago. Still looks showroom new. I painted only the tank -- didn't paint the fins. They looked OK and I didn't want to affect heat transfer.

I masked off the fins. Primed with two coats of rattle-can Rustoleum Self Etching Primer and lightly knocked down any rough spots with a ScotchBrite pad. Then rattle-can Rustolium Black Semi Gloss Protective Enamel: one light coat and two medium coats, the last a little wetter.

The radiator tank is brass. The primer/paint has stuck to the brass perfectly.

Photos in this link may be slow to load.
http://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=841125#Post841125

Lonnie
TF7211

image - painted radiator

LM Cook

I'm with Lonnie; why paint the fins? They are made using non-oxidizing metal so they should last longer than most other parts of our cars and painting them WILL reduce heat transfer. The rest of it, sure, paint it.... any black will do :)
Geoffrey M Baker

The fins are copper, and copper does oxidize. It is good form to paint them. Black transfers heat better than other colors, which is why radiators are always painted black. In any case, painting the radiator will make little to no difference in cooling ability.

Never liked bare brass tanks. It looks good on a brass era car where the radiator was designed to look pretty and show from the outside, but there is nothing attractive about a T-Series radiator, and nothing else brass on the car to tie it into the overall look. I especially hate it on MGBs and the like. Looks so out of place, and draws your eye away from the things that WERE designed to look good.
Steve Simmons


There are three (common) forms of heat transfer.

Radiation,
Conduction,
Convection.

Only in radiation does the emissivity (Color) become a factor. (However radiation is proportional to the differences in the fourth power of the absolute temperatures of the source and sink.

Since the radiator is covered and cant see much of the outside world, its temperature and the temperature of immediate surroundings is close.)

I would believe that the heat transfer from the radiator is primarily Forced convection.

In that case whether the core is painted black or red or even silver wont matter. The actual heat must be conducted through the paint to the air stream (by conduction) then into the air stream by convection. The best paint in that case would be no paint.

(or perhaps aluminum)

The copper, if left unpainted, will eventually form an oxide and develop a black patina.

I would paint the frame and leave the core to do its thing.

Jim B.
JA Benjamin

I'm with Jim. Copper, like aluminum, forms a surface coat of oxidation (called tarnish, which will turn black) but it will not degrade further, so painting will not protect it in any way. All paint can do is reduce the thermal transfer of heat from the water to the air, which is never good.
Geoffrey M Baker

If you can detect the difference in cooling between a painted radiator and an unpainted one, then you're a heck of a lot sharper than I am.
Steve Simmons

It seems to me that keeping a cooling system running efficiently consists of adding up small increments of improvements. Painting the radiator is just a small increment of disimprovement, efficiency-wise. Add it to slowly clogging fins, dirty water, an aging thermostat, leaks, a choked up engine block... it adds up over time. That's all I'm saying.
Geoffrey M Baker

I lightly sand and then clean the debris with acetone. I use Flat Black, a very thin coat. Rustoleum is a good paint for protection, but to accomplish this it goes on thicker, so I would not use it on the fins. I'm not a fan of the bare brass look. You can straighten the fins with a small screw driver blade if you are patient enough.

Warmly,
dave

Dave Braun

The cooling system on a T-Series is more than adequate to cool the tiny engine. Keeping it running efficiently only means maintaining it in as-new condition. If the car is running hot then something is wrong, and stripping paint from the radiator will do absolutely nothing to improve the situation.

The system is either in proper condition or it isn't. If the block is clogged, it needs to be tanked. If the radiator is clogged, it needs to be rodded or re-cored. There are no shortcuts to be had, only preventative maintenance to keep things clean and clear. The only improvements I've experienced were in extremely hot climates... a 6-blade impeller, which makes a small difference, and at low speeds a more efficient fan can help. But in normal driving, a T-Series MG should have no trouble even well at over 110F ambient temp. One of our local members has no fan whatsoever and I've never seen him overheat, even when he joined our caravan of T-cars through the Mojave Desert in Summertime. And in that caravan there was no overheating, and that's a hotter situation than anything 99% of classic car owners will ever put their cars through!
Steve Simmons

As far as brass, seems like most people think it's "too much". I don't know if I'll paint the radiator tanks black or not, but I do know that the reason that MG and other manufacturers were busy painting brass was because in the 1950's, steel and plastic was rapidly replacing iron and brass - and for most people back then, brass looked OLD and out-of-date. It was reminiscent of steam engines and turn of the century technology.
Nowadays, brass is a great accent on an old car, if you ask me. I see no reason if people like it that they shouldn't strip off that cheap black paint and get out the Brass-O and start polishing!
Geoffrey M Baker

More likely they were painted black to make them look nicer. The piece was not exactly "styled" so making it disappear would make the whole engine bay look better. Besides, brass would have been pretty nasty looking by the time the cars were sold, especially those shipped across oceans.

If the radiator was meant to look nice on its own then I'd leave it brass, but it's a pretty ugly piece of equipment. Pure function. No one wanted a brass radiator in the 1940's and 50's because it was 20-30 year old styling. Even Model Ts switched to painted front ends in the second half of production. So manufacturers stopped making them look good and turned them into a basic component, like a water pump or an ignition coil.

Brass radiators were used right up into the 80's but you never saw a brass one on a car since probably the 30's!
Steve Simmons

This thread was discussed between 07/04/2015 and 10/04/2015

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