Is it desirable/ok to paint rad matt black?
Tim
to be honest, unless you really have some need to, i'd avoid it, it'll stop it working quite as well.
Yes at the moment, but check SVA wording nearer the test re. exact colours allowed.
not to give dissinformation, to be honest I'm not 100% sure, but I thought black radiators dissipated heat better than unpainted because of the dark color,
quote:
Originally posted by zetec
Yes at the moment, but check SVA wording nearer the test re. exact colours allowed.
You don't need a locost in Brazil, just get down the beach and soak up the view...
Which only makes it "harder" to get back into your locost
rads are balck as std, to increase heat dissipation, so how can painting it make it worse.
sva????? where does the sva specifiy rad colour!!!!!!!!!!!!
atb
steve
We've got a bite! Reel him in!
Apparently, the most efficient paint colour for domestic heating radiators is silver (or gold). If the car rad is bare ali, then it's probably
best to leave it as it is.
DJ
[Edited on 28/7/04 by David Jenkins]
Is it OK in sva to use silver jubilee clips on the hoses, or do they need to be rad compliant colours too?
atb
laurence llewellyn bowen
quote:
Originally posted by David Jenkins
If the car rad is bare ali, then it's probably best to leave it as it is.
DJ
[Edited on 28/7/04 by David Jenkins]
I quite sure that a light dusting of matt black won't make a lot of difference to heat transfer rates - just don't slap it on too
thick...
David
Interesting question, so did some Googling on it. Here's a good explanation of modes of heat transfer (conduction, convection, radiation):
http://www.physchem.co.za/Heat/Transfer.htm
Radiators work by convection in getting the heat out of the engine via the moving fluid, then by conduction to the outside air. Radiation via
electromagnetic waves (in which color makes a difference) is minimal.
Probably best to use standard radiator paint because it is nice and thin, but first have the radiator dipped to remove any old paint and corrosion,
for better conduction.
Unless it's an aluminum rad, in which case it's better not to paint at all. Brass needs to be painted. Interesting discussion about ally
vs. brass here:
http://www.eng-tips.com/viewthread.cfm?spid=108&newpid=108&sqid=61247
Pete
SEE, HAHA, IN YOUR FACE, 
, I WAS RIGHT BLACK IT IS, (just not if it's aluminum).
[Edited on 28/7/04 by derf]
The main point is that it's not the colour that's the main concern, but the insulating properties of the paint.
Give it a nice thick coat of matt black paint, and its efficiency will drop significantly... but a dust-over will do no harm.
So there - na-na-nana-na!
David
unless its my special magic black paint.
only 200 quid a litre.
buy from me now and aoid the rush.
atb
steve
jeez! ok, mine is ali (btw very difficult to find a small enough rad here, even 1.0 cars have big rads. wonder why...)
wanted to paint it black to lose it, yes. it is new too. intend giving it a dusting of matt high temp spray paint
'cept of course painting ali is a no no...but dont know why and the link didn't work...pete...
Oops! Looks like you need to register to read.
Eng-Tips is a very cool website, btw. It's a discussion forum for professional engineers, everything from cars to oceanography. I joined so I
could read a link, and forgot that I had.
I just read through a little more thoroughly, and the point was made that OEMs paint their ali radiators for corrosion resistance. So no problem
painting yours, but you should use a proper radiator paint so you don't obstruct the fins, or add insulation.
Pete
OK pete, thanks mate!
paint doesnt key well to alu unless its etch primed - so im told.
However, a dusting of black on a rad to make it a bit more 'hidden' shouldnt be too much of a problem.
Paint coming loose in time on a rad isnt the same as the paint falling off your car body!
BTW - many small engined cars in the UK also have quite big rads. The tendency seems to be to have a wide thin rad, rather than the old ways of thick
and square.
Im guessing that this may be a requirement of modern cars, where they try to hide the air intakes to the rad as little styling slits, rather than big
open apertures.
atb
steve
Steve,
yeah, have to agree there, they are all very thin, look like they could bend under their own weight! The one I found is definately thicker...its from
a Fiat 147!!! New old stock.
I've owned most of the Fiat range at some point, but never a 147!
i have to say, there is no point in painting a radiator to help it lose heat. Any increase in heat transfer will be minimal, it will be counteracted
by the equally slight reduction in air flow, the insulation of the paint etc. Plus you usually dont need greater cooling, if you do its probably
caused by a lack of bonnet ventilation, so if the radiator did pump out heat better the engine bay would just get warmer and the intake air would be
hotter and the engine would explode.
ok, maybe im getting a little carried away there...
if you want to paint it cos it looks crap, fair enough. If your engine is over heating, get the rad well cleaned, straighten any bent vanes, and most
importantly add some bonnet vents and ducting.