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]

You're talking about the point in that video, right?

Yes, and it also applies to this discussion.

1 - Yes black paint will help the push rod tubes radiate heat better (but they will also absorb heat better)
2 - The black paint does not change the convection properties at all (positive or negative) contrary to your comment:

"Bare metal (aluminum anyway) convects heat best, and that's science"

Although the truth is that certain surface preparations DO help convect the heat better if it increases surface area and does NOT provide an insulating layer. An aluminum flame spray coating would help convect heat better than a polished aluminum surface.
A rough plastic coating would HURT the convection because it would decrease conduction of the heat to the surface where the convection takes it away.

3 - The emissive properties of the tubes (painted or not) is meaningless because the contribution towards cooling is orders of magnitude greater for Convection than it is for Radiation.

So trying to optimize convection is a much greater return on investment than optimizing radiation.