Under side of rear clip

How are guys treating this??

Some more newbie questions:

Do you just have the body/paint guy prep it and paint? It seems many in the pictures are black on the underside. Is it painted that way or some other coating? How do you deal with heat from the exhaust?

Do most people ceramic coat the coolant pipes running to the front of the car to avoid rust issues? Are these pipes part of the chassis or separate parts?

A good point, Scott.

The only fer-real GT I'm acquainted with here in the NW is owned by Doug Kirk. His car (perhaps one of the other forum members from the Seattle area recall his chassis number) has an insulated 'blanket' secured to the inside of the rear bodywork. Interestingly, the inside surfaces of the rear clip aren't black but, for the most part, it matches the exterior color which currently is a baby blue

You'll definitely need some heat shielding on the underside of the clip. I used DEI heat shield. http://www.designengineering.com/products.asp?m=sp&pid=27 This along with a ceramic coated exhaust really reduces the under clip temperatures. Coolant pipes are not as big an issue although you might spend the dollars for stainless to avoid any corrosion issues.

I believe Doug's car is 1117, Safir chassis MkV.

I'm planning to spray the inside of my front and rear clip flat black, prior to the application of the heat shielding material. Since I haven't sprayed a car in 25 years, it's a good place to start and get a little practice.

I plan to use some form of undercoating like truck bed liner or Lizard skin. It is a good idea to do something in the wheel well too. Otherwise stones off the tires can star the paint. I may also use a stick on heat shield over the exhaust.

I talked to the guys at Herculiner and they said it's only rated to 254 degrees and it will start getting sticky. I guess that option is out. Maybe the other brands have higher heat ratings.

Underside of Rear Clip

Jonathon, try glueing 1/8 thick high density cork to the inside of your fenders were rocks and stuff might fly into the fiberglass and make stars. I sprayed regular undercoat over this and it has worked well for several years - even under track use.

Some owners of aluminum Cobras use 3/8" closed cell foam glued to the underside of the wheelwells to prevent stone damage.

Be cautious!

I learned the hard way. In trying for heat protection as well as sound insulation, I lined the underside of the rear clip with Cool It thermal and sound barrier. The asphalt-like carrier melted onto my beautiful ceramic coated pipes and all over the engine, taking me 3 days to clean up. I currently have Thermotec heat shield and it works but doesn't seem to stay. The adhesive just doesn't last in the heat; particularly the area directly above the bundle of snakes. I'm still looking for the right stuff.

BTW Dynamat works well in the wheel well roof, both for reducing road noise as well as chip/rod debris protection.rockonsmile Just clean the underside thoroughly before application.

diecast18 said:

Some owners of aluminum Cobras use 3/8" closed cell foam glued to the underside of the wheelwells to prevent stone damage.

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That's what I have in my Kirkham. Works very well.

I have also talked with car buffs that used thick heavy under hood materials that ultimately did not withstand the temperatures of the engine compartment. Either the adhesives holding the insulation to the hood would fail or the material itself would soften, drip, and smear especially at the edges.

Because the Phoenix summers are so hot, some weeks of 115F plus, a hood liner really gets severely tested. Lots of car guys here in Phoenix use the DynaMat Hoodliner stuff. This stuff is very light weight, has nothing inside to drip, and sticks like crazy.

A couple of years ago Dynamat (dynamat.com) "Hoodliner" P/N 11905 was $70.00 for a 55-1/2" x 32-1/2" sheet 3/4" thick. The engine side is a thin water proof aluminized heat reflector. It feels like Mylar. The inside has a closed cell acoustic foam center with an acrylic adhesive backing.

After two years on my car, Hoodliner is still shinny and unwrinkled. The disadvantage, depending on your preferences, is that shinny aluminized outer skin stays shinny and would probably be difficult to paint a dark shade. There may be something better out there but this is worth a look. Good luck with the search, this is question that everyone has at sometime during the course of their build.

Bob

Any recommendations for adhesive that "works" in this high heat area on the underside of the rear clip? By the statements above, nothing has been mentioned that works 100% .

This adhesive: http://www.designengineering.com/products.asp?m=sp&pid=29 is supposed to be good for continuous temps up to 500 F.

And their Floor & Tunnel Shield product: http://www.designengineering.com/products.asp?m=sp&pid=27 already has an adhesive backing, which is supposed to be good for 450F.

Excellent, thanks JohnC. Have you used this product with success?

Tim, no I have no experience with it - just happened to find it while browsing. Neil also posted a link to this website, so perhaps he's had some experience with their products.

John

It might be a bit of work but I was thinking you could glass in a few studs that could go through the insulation and then secure with fender washers and nuts similar to the way they secure insulation in a marine engine room

Tim,
I was thinking along those lines as well. Maybe use some thin aluminum strips around the edges and down the center held on by the studs. That way it wouldn't require too many studs to be glassed in.