insulation questions

[Jim Rosenthal]

There's a gold foil material in the Pegasus catalog, described as "gold-colored heat reflective film" p108. This LOOKS like the material that was used under the bonnet of the McLaren F1 car, but is clearly not the same stuff at the price. Has anyone used it and could they report on how well it worked or didn't work?

I think most of these heat-reflective materials work fairly well, maybe better than that. I don't know how well the adhesives hold up, though. This stuff, because it's light, might work well because it would likely stay where it was supposed to even when heat softened the adhesive.

I also found out from a friend who's building a racing Miata on a budget that he's using a heat-reflective material called Reflectix (Lowes) which is basically plastic with air bubbles with aluminized Mylar film on both sides. He got the idea from a Corvette racing site that claimed it worked very well at heat and sound insulation. Has anyone here used Reflectix? I'd be curious to know how it worked out.

We are getting to the point where we're going to have to face these sorts of problems in the fairly near future, and I would like to know what other folks have done about trying to keep engine heat in the engine area, not have engine heat cook the rear bodywork, and keep tunnel heat in the tunnel. I know these things have been brought up in the past, but I don't think these two materials have been looked at here.

Thanks in advance for any contributions.

 

[Seymour Snerd]

Jim --
I've used reflectrix for bulding insulation (eg aluminum garage door facing the equator). Although it is a pretty good thermal barrier and very inexpensive, I don't think it is effective in reducing acoustical transmission. It might have some effect as an accoustical absorber but I would expect the foam-type materials (eg Dynapad) to be vastly superior in both absorption and transmission. Its mechanical properties are very much like a heavy bubble wrap.

I would also be concerned about the melting temperature of its plastic film component. As you will see at the mfr. FAQ page
Reflectix Inc. | All About Reflectix® | Frequently Asked Questions

it is rated only to 180 deg. F which I think is too low within the engine compartment or near any cooling system components, but probably OK for the interior eg the inside of the rear bulkhead. As bullding materials go it is very light and its R-value without airgaps on either side is 1.1 (in case you want to compare it to conventional building insulation, although that's an odd reference to use for cars since in buildings you typically have 3-1/2" or more space to work with).

 

[Doc Kaler]

Jim,

I'm using the gold foil in my SL-C build. I researched this stuff for quite a while trying to find an "Uber Foil" with better properties but found none. Unless McLaren is making their own version, all other vendors sell the same material. Sorry, but I don't have any data for you yet as the build is underway.

 

[Jim Rosenthal]

Thanks to all. I think we will use the gold film on the underside of the engine compartment area; the rear clip. It isn't hugely expensive and it ought to work fairly well to keep the bodywork from getting too hot. We don't have a shield over the mufflers, but we may find we need one.

Your point about Reflectix taken. I had thought to use it to line the inside of the passenger compartment, like the outside of the tunnel and the inside of the rear bulkhead, but I think I'll use Dynapad as you mentioned. The areas aren't that big and I'd hate to have to do it twice.

When I get around to insulating the garage, THEN maybe I'll try Reflectix.

 

[Seymour Snerd]

When I get around to insulating the garage, THEN maybe I'll try Reflectix.

The rest of that story is that I ended up tearing off the reflectrix and replacing it with cut-to-size polystyrene insulation panels which worked far better, and who's thickness was essentially perfect for that particular door.

 

[Randy V]

Here's another thread that we had not long ago on the subject;

http://www.gt40s.com/forum/gt40-tec.../28635-rear-clip-inner-lining-insulation.html

 

[Chris Duncan]

I used "Cool It, Thermo Tech" from Aircraft Spruce for the back deck good to 2000 deg F, and the black fire resistant aircraft foam for the passenger compartment, very light.

Dynapad is a little heavy and don't think it's fire resistant. Same with Reflectix, that plastic has bad fumes when it burns.

 

[Jim Rosenthal]

I just got a catalog from AS when I got Clecos. I'll look for the materials you mentioned. I don't want to have to do this twice, God forbid.

 

[Chris Duncan]

aircraft spruce is online

here's some pages from the insulation and soundproofing sections

Insulation from Aircraft Spruce

Soundproofing from Aircraft Spruce

 

[Russ]

My buddy I'm sharing a garage with is using the gold reflective foil on his fab'd aluminum air box and also the aluminum intake tube for an LS383.
No before or ofter testing of the IAT's, looks neat though. Just don't put any self tapping or other machine screws through it, it twists with it and doesn't look so neat around the head.

 

[Neal]

Jim,

Check out Design Engineering products. I used the diamond patterned material on the back of my rear clip. It really does the job. If you are married to the gold material they also have some options.

Design Engineering DEI 050503 - DEI Floor and Tunnel Shields - Overview - SummitRacing.com
Design Engineering DEI 010393 - DEI Reflect-A-GOLD Heat Barriers - Overview - SummitRacing.com

For some reason, every time I see the gold stuff I hear the "A-team" theme music!?
I pity the foo who doesn't use insulation...

 

[Randy V]

For some reason, every time I see the gold stuff I hear the "A-team" theme music!?
I pity the foo who doesn't use insulation...

While I liked the "A-Team" show for it's entertainment value back in the day - I thought the Mr. "T" Bling factor was stupid..
My personal quest for insulation is for the highest amount of heat reflectivity / insulation with the thinnest profile when installed.
So far I've not found anything that exceeds the 80% reflectivity of most of the gold foil barriers...
So - bling be darned - I will most likely end up with the gold...

 

[Thomas Rouw]

the original Gold reflective film that was in the mc-Laren F1 engine bay, is a material engineered by ESA (european space agency) "the euro NASA" for that matter, and was specificly desinged for use on the french Ariane rocket's fuel tanks.
it's still used widly in the manufacturing proces of sattelites these day's

altough it can controll heat very well it can controll cold even better.

I've heard several people say that it is for sale at the better aircraft building shops so maybe spruce will be able to tell wheter theirs is the real deal or not.

the stuff isnl;t manufactured by ESA only engineered, so it could well be true.

Grtz Thomas