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OK to paint the controller black?

Posted: Sat Mar 28, 2009 12:31 pm
by badnewswade
Hi there, a quick bit of advice - I'm painting my moped and was wondring if I should mask off the controller or if its' OK to paint it? Wouldn't painting it black cause it to get hot, and therefore be a bad idea, or can I have it any colour I want? What if I painted it a bright colour (I was thinking of bright yellow or purple, something outrageous anyway)?

Here's a pic anyway, so you know what I'm talking about:

Image

Posted: Sat Mar 28, 2009 2:04 pm
by MalcolmB
Curiously enough, the colour with the highest emissivity in the infrared range is bright pink.

Posted: Sat Mar 28, 2009 3:55 pm
by microman
Perhaps, depending on the shade, but not as high as a true black body radiator which has an emissivity of unity. So matt black (a non colour) is usually better than anything else which is why most heat sinks are anodised or painted black.

Posted: Sat Mar 28, 2009 7:53 pm
by badnewswade
But won't black absorb heat from the sun? I'm now thinking of that dirty shade of day-glo yellow or green, so if that helps keep the heat off the controllers electronics, all the better. I was inspired by a photo I saw of a survival bike where they actually painted the engine that colour but I cant find it again... doh!

Posted: Sun Mar 29, 2009 3:48 pm
by microman
Yes, in the sun black (and any colour) will absorb heat. So overall you'd probably be better off leaving it shiny aluminium and relying on conduction to the ambient air - that's what the fins are for. Unless the surface is very hot the major heat loss is conduction and not radiation especially when you're moving.