header wrap is notorious for condensation build up, over time. I'd look for some silicone sheets . OR buy silicone mats, make sleeves from Nomex with pads in between. . some kind of snaps to hold access side for replacement as needed.
http://www.amazon.com/s?ie=UTF8&page...ads%20silicone
This one here is nice, already formed to shape.
http://www.amazon.com/Lodge-ASHH11-S...nd+pot+holders