[Amps] Anodizing aluminum, painting etc.

[Tom W8JI]

> layer, not the dye per say. It may add to it, I don't 
> know. The way I was always
> taught was black absorbs heat, and anything bright like 
> white or silver reflects it.
> I would think the mass or thickness directly under the 
> device is what will help
> keep it cool, and the find transfer the heat to cool it 
> off by the air circulating past
> them. I can't see where black would help this at all, 
> unless they say the black
> helps with the heat transfer to the air.

Black or dark colors aid in infrared exchanges in both 
directions. This is why thermos jugs or bottles are the same 
shiny clear surface no matter when used for hot or cold 
liquids and heat exchangers that are not exposed to external 
heat radiation are often black.

Aavid, a leading manufacturer of heatsinks, even advises it 
is a good idea to use a black or dark anodized heatsink to 
aid in radiation mode heat transfer unless the heatsink is 
facing a hotter object nearby.

Black isn't a diode. Like a good antenna, it both radiates 
and receives both directions better.

73 Tom