JAY DE

Work in progress....
Apr 4, 2007
106
0
Sunny Essex
Can anyone recommend a company that does thermal coating..?

I want to get my DP and manifold coated before the new turbo goes in.

:D
 
Because the effect on the surface temperature is negligable. You have a coating that's at most 0.1mm thick. At that thickness, to achieve any useful reduction in temperature it would have to be far more effective than any known heat insulator.

There will be a small reduction in the heat is lost by radiation if the coating is white as opposed to stainless steel that goes black after a while. The reduction in convective losses would be maybe a few %.

Bernard
 
so what do you propose I do?

If I use heat wrap that will retain moisture and eventually make everything rust :confused:
 
all due respect bernard... bollox... ;)

massive reduction in radiated temps on my ceramic coated manifold.. not camcoat tho
 
Hmmmm, well I still think it's snake oil. Compared with a black manifold and downpipe then OK you will see maybe 30% less radiation but I can't see it affecting underbonnet temperatures that much.

But if you reckon it works on your car Bill then that's good enough for me, but I would like to see some before and after numbers to be convinced.

Bernard
 
I have decided to go doen the heat wrap road because i will be using my car quite often and i have been told that the wrap will be better for me :D
 
I have decided to go doen the heat wrap road because i will be using my car quite often and i have been told that the wrap will be better for me :D
i have some unopened heatwrap in my garage if you want it;)
 
all due respect bernard... bollox... ;)

massive reduction in radiated temps on my ceramic coated manifold.. not camcoat tho


I'm with Bill on this one, the decent ceramic coatings have approximately 4x less thermal conductivity than normal untreated stainless steel (approx 5w/m2 vs 21). Hence the radiated heat (for any given surface temperature) will be 4x less.

The only choice is how much money to spend on your coatings, the more you spend the better the heat retention and the less likely the coating is too flake off the part underneath etc.
 
It's not simply down to thermal conductivity. It also on the thickness. OK, so the coatings have worse conductivity than steel, but they are very thin. If you have say 800ºC at the steel tube surface then to reduce the radiation by a factor of 4 the temperature of the coating surface would have to drop to 566ºC (from the Stefan-Boltzman equation). How are you going to drop 234º across a coating only 0.1 mm thick ?

Bernard
 
Bernard
As max says it's all about the speed at which the heat can leave the surface, not about a drop in surface temperature.

The coated manifold will probably run hotter than the uncoated one, but will radiate less heat to the surrounding air. It is not like heat wrap where you actually insulate the surface.
 
Bernard
As max says it's all about the speed at which the heat can leave the surface, not about a drop in surface temperature.

The coated manifold will probably run hotter than the uncoated one, but will radiate less heat to the surrounding air. It is not like heat wrap where you actually insulate the surface.

And what determines the speed at which heat can leave the surface ? The temperature, the rate of airflow passing over it and the colour.

We are not changing the temperature much, we are not changing the rate of airflow, we are changing the colour but this does not make a huge change to the heat lost.

I'm still not convinced, any of the suppliers got any data ? Can't see any with actual measurements.

Bernard
 
And what determines the speed at which heat can leave the surface ? The temperature, the rate of airflow passing over it and the colour.

We are not changing the temperature much, we are not changing the rate of airflow, we are changing the colour but this does not make a huge change to the heat lost.

I'm still not convinced, any of the suppliers got any data ? Can't see any with actual measurements.

Bernard

according to max's figures, it quarters the speed at which the heat is lost from the surface.
I'd say that was a big difference.
 
according to max's figures, it quarters the speed at which the heat is lost from the surface.
I'd say that was a big difference.

You seem to be missing the point, it can only reduce the speed to 1/4 by reducing the surface temperature by 234ºC. It can't do that with such a thin coating.

Trust me, I've spent 25 odd years measuring heat transfer in a laboratory.

Bernard
 
i think it lies somewhere inbetween (from whom i have spoke to) it slows down the heat transfer, but does not eliminate it (i sell stainless heat exchangers)
 
You seem to be missing the point, it can only reduce the speed to 1/4 by reducing the surface temperature by 234ºC. It can't do that with such a thin coating.

Trust me, I've spent 25 odd years measuring heat transfer in a laboratory.

Bernard

Barnard
Heat lost by a surface = temp diferential between surface and air X heat transfer coeficcient x area.

If you drop heat transfer coefficent by a factor of 4 it has the same effect as reducing the temperature differential by the same factor when you look at heat transfer from the surface.

With a moving fluid at the heat transfer surface it gets more complicated, but the basics are still the same.

Anything technical written by Max Torque is fact. I wish he posted a lot more so that we hobby tuners could poach/apply more of his (and his employers)insider knowledge, thats come from r&d budgets we can only dream of.

If you think it makes no difference, ceramic coat your intercooler core.:p