heat shield

windrose · Post by **windrose** » Mon Nov 24, 2003 8:57 am

Hey Guys, just found you off the boat building ring. I'm rehabbing #215 and was wondering if anybody has tried this stuff as a head liner or redoing their ice box. Any comments?
www.heatshieldmarine.com

Post by **Tim** » Mon Nov 24, 2003 9:24 am

Welcome to the forum!

I've seen that Heat Sheild stuff before, and they certainly make some persuasive claims, but I have no practical experience or knowledge about it. I could see how it would be nice if it truly reflects the energy the way it says, especially on areas with hotter sun. What would be the ultimate would be to have a layer of that stuff sandwiched out of sight between the cabin liner and the deck. How would you plan to install it on the cabin trunk?

Whether or not it's worth it on an icebox is something else. I had good luck with 4" of polyisocyanurate foam (foil-faced), straight from the home center. It's something like R 7.2 per inch. Perhaps the Heat Shield is better because if could take up less room for the same insulating qualities (but for 10X the price per sheet--yikes)? It's not too tough to find room for 4" of foam in a new icebox build, and it works great.

windrose · Post by **windrose** » Mon Nov 24, 2003 11:45 am

Tim, first off I want to thank you for a first rate job of documenting Glissando's rehab.... I have spent many hours pouring over your site. It always stirs me into some sort of action (along with Ray's Pegasas project). WOW!

I was thinking of installing it as outlined in their brochure by epoxying some ribs to the cabin top. My biggest concern is the amount of condensation I get on all the outside walls. When I got the old gal someone had put this awful shag carpet throughout the boat (glued to the bulkheads, the walls of the v berth, the sole, etc---- awful stuff).... when I pulled all that out, everything was covered in mildew. I sprayed everything down with chlorox and water, primed eveything with white mildew resistant paint. I am in the middle of installing ceiling boards along the outside walls of the v berth to make it more asthetically pleasing but keep good air flow going. (vertical stringers epoxied in place, horizontal slats cut, sanded, getting second coat of Cetol, almost ready to install).

I have improved the air flow with a solar fan and I no longer have the mildew smell, but I guess I am hesitant on any sort of head liner because of the condensation. It gets really hot here on the Chesapeake in the summer months and so I am intrigued by the heat shield but hate to be the guinea pig. Thanks for your comments or suggestions. Angie (Windrose#215)

windrose · Post by **windrose** » Mon Nov 24, 2003 11:51 am

:D.... I had to chuckle when I noticed "bottom sanding grunt" as that is so very true, I've gotten the 7 layers of paint off the starboard side and am slowly making headway on the port side.... I guess I easily have 30 hours in sanding alone and only have one side and the doghouse sanded....I had no idea I could take such satisfaction in low back pain! AAARRRGH!

Figment · Post by **Figment** » Mon Nov 24, 2003 2:28 pm

Tim wrote: I had good luck with 4" of polyisocyanurate foam (foil-faced), straight from the home center. It's something like R 7.2 per inch.

Tim,
I recently attended a roofing seminar, and learned that polyiso is about to be "downgraded" to something in the neighborhood of R6/inch because of new testing standards which account for degradation over time. It's R9 when it first leaves the factory, but three or four years later it's down to R5 or so. This is partly because it slowly accumulates atmospheric moisture, and this stuff isn't worth a damn once it gets wet.

I used to be a big advocate of polyiso, but it looks like extruded polystyrene is about to make a big comeback. Near-zero moisture degradation.