I've noticed that shiney polished aluminum airplanes are quite hot in the
sun, whereas white and light cream colored painted exteriors are quite cool.
I used to think and "aluminum" finish would be best for reflecting heat, but
I no longer think that.  I think the same situation would prevail inside the
cowl.

David

----- Original Message -----
From: "Chad Robinson" <crj@lucubration.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Sunday, May 23, 2004 9:25 PM
Subject: [FlyRotary] Re: Two problems solved, 2 more pop up...


<snip> Given that the primary goal is reflecting radiated heat (rather than
"real"
> thermal insulation) what's wrong with a coat or two of shiny silver paint?
> It's not as good as polished aluminum but it's decent, and high on the
> reflective scale. Sherwin Williams (and others) sells a product called
> "Silver-Brite" that is marketed as "heat reflective" and "dry heat
resistant
> to 700degF". I haven't tested its adherence to epoxy so it might need a
primer
> coat to help it stick better (it's designed for metal) but that's not a
> painful step. In any event, it would sure be a lot easier to apply than
either
> foil OR fiberfrax, especially to an oddly-shaped cowl.
>
> Unless real thermal insulation properties are necesary?
>
> Regards,
> Chad