Puckster wrote on Mar 18^th, 2013 at 3:06pm:

Mad_Birdman wrote on Mar 16th, 2013 at 1:29am: Ha, well that would make more sense now wouldn't it?! On a sunny paddling day, you will need to have your sunglasses on! I'm considering wrapping my entire barrel with it.  Does anyone have experience with this stuff?  Does it have strong adhesive?  Is it tough, or will it fall apart after the first portage?  And yes, by the looks of it, I will definitely wear sunglasses! prouboy

I'd consider painting the barrel with aluminized/white paint and then lining the  interior bottom/sides/inside top with a thin insulating material.
Somehow I don't think wrapping barrel would hold up for very long on portages or with those little camp critters chewing on it. :-/