push rod tube, to paint or not Options

[jacksun]

Hi,

got my first push rod tube cleaned up and would like to paint it with

hi-temp paint? any problems doing so?

tks

randal

[stugray]

but in this or that application who really cares about radiation?

That's exactly what I have been saying as well.

with an engineer going through the math and apparently contradicting both the conclusions in that Mighty Mods video and some of your points:

Nothing the engineer said in his video contradicts what I said above.
My explanation above was merely in response to your statement :

Sorry, can't believe that, no way. Bare metal (aluminum anyway) convects heat best, and that's science. What manufacturer can you think of who paints their aluminum radiators or intercoolers? Radiator paint was used back when radiators were brass to reduce corrosion, which did reduce convection, but even unpainted brass transfers heat better than painted.

Martin Marietta (Now Lockheed Martin) patented the best "Radiator Paint" known to man.
It is called "Martin Black" and has been used to paint radiators by the military for years.
It is known for it's emissive properties but help cooling by convection as well.

One way to think of it is:
If you polish the metal surface really well, the air will move over it in a laminar flow and have little actual "contact time" with the surface.
If you make the surface rough by either sandblasting it, sanding/etching it or coating it you can make it transfer heat better by convetion than bare polished metal.
It does this by causing more turbulence near the surface.

So you CAN make a surface better at convection by changing it's surface properties.

Sandblasting or aluminum plasma spray would make a much more effective convective surface than polished aluminum.

Would a paint be better than polished aluminum?
Not likely if you choose your paint at random, but definitely possible.