Source for thermal insulation?

[Steve O'Hara]

Howdy,

Anyone know of a source for the stainless steel/fiber sandwhich thermal insulation used on the DB4 to protect the side pod and engine cover from the heat of the exhaust header?

In lieu of that material, any recomendations for and alternative that would be as effective or better? Is the gold reflective material sold by Peguses suitable for the application?
Thanks
Steve O'Hara

[Rich Domikis]

Two ways to reject heat - boundary layer or reflection. The silver thicker pads are basically boundary layer with some reflective qualities. Just like silver backed home insulation.

The gold material is intended to be infra-red reflective material. Note there are many woh make "cheap gold" heat shields and they don't reflect IR and hence will not work. If its not $20-$50 a foot it's not the real stuff. Might be cheaper now or in non-spec stuff (not good enough for aerospace but good enough for racers.

I didn't know Pegasus carried the gold stuff - I'm lookking too so I may get some and see. They're a good group and expect if they sell it then it's the good stuff.

Is it good enough? How is it applied? That is also a trick since a zillion degree material held up with less than the right "glue" doesn't really help.

For areas close to a constant heat source you need to think about heat soak. Even if a little heat gets through after a 30 min. session you have built up heat and the blanket that protects you now keeps whatever got in in. That's why many ALMS teams went to gold film. With correct air management things don't get too hot and cool off quicker. It's lighter too. Straight from the space program. And I guess looks high tech/cool….

You might remember the silver blankets handed to exposure victims. The goal was to reflect their lost heat back to their bodies.

The foil usually has a lower maximum op. temp. I guess below 1000 deg really more like 500.

Mats on the other hand can go way up to over 3000 deg depending on the material and thickness.

For us EGTs are about 1000-1500 nothing really more - unless you run a jet. If you consider that most of that goes out the exhaust radiant heat from the exhaust is the concern.

I'm thinking of jet coating the pipe to keep the heat in until it exits at the rear and thin foil the areas I want protection. You can heat wrap the headers instead but then looking for cracks isn't fun and the wrap causes more cracks - heat soak again...

I'd also consider protecting the fuel cell from heat with the foil as well. and the air box , and, and, and..... anthing where cooler is better

Last and perhaps most important air flow management vent and route air so that radiant heat is forced to leave. A few small NACA ducts or exit gills will help when moving - don't do squat when still.

I'm still working tub mods so you'll probably try the gold stuff first - let me know how it goes! You have to coat or wrap the exhaust that is the key!

rich

[Charles Warner]

I vote against ever wrapping the headers. Rich, on both my 89ds I had the headers coated by HP in Mississippi and did not have to use any heat shielding on the major parts of the bodywork. I did have a small area on the inside of the engine cover just where the tailpipe exited and that was the silver stuff Pegasus sells with high temp RTV holding it in place. There was never any evidence of heat problems.

[Rich Domikis]

Charlie,

I agree... Coating is way better. I had a SV with wrap while the outside is kept cool. The "heat blanket" causes internal crossion and higher chance for cracks (ones you can see easilly). The cool off of a coated pipe is much faster.

About what did it cost you for coating? Do you have a contact number for them? I have a friend Mark Parnel who owns a coating company - lost touch with him. I'm hunting for his company name and number.

rich

[Charles Warner]

Rich,

Don't remember the prices. Last time I used them was 5 years ago on the Lola and the headers are still great.

Here's the website www.jet-hot.com

[ZEKESPEED]

The Gold Film works great to protect body work, battery boxes, bulk-heads etc. Used by most Indy/Champ/DP car teams, Ferrari, BAR F1. 5oz sq yard. reflects 78% of all radiant energy. C&R distributes this material. Sold by the linier foot (1' X 24'') also sold by the 150' roll. Call for pricing 317 293-4100

[aeroresearch]

I just applied way too much of this foil to a porsche project and due to its cost I have some freindly advice. Make sure what ever your applying it to is VERY clean. The adhesive it is backed with is very good but does not tolerate ANY contamination. Also it does not really like to stick to unfinished composite. Any fiberglass or carbon surface must be smooth sanded and primed to provide the most surface area for adhesion. It really sucks to waste any of this stuff especially with the recent upturn in the price of gold.

[Shep]

I saw this page when searching the Coast Fabrication site:

http://coastfab.com/specials.html

Interesting technical details of the offerings regardless of whether you purchase the Coast Fab stuff.

[TimW]

Use silicone adhesive as well as the stickum that is on the film If you only use stickum on the film and apply it on bodywork above the header, it will eventually fall onto the header and catch fire. Its heat resistant, not fire resistant and will burn if touching the headers.

[Rick Ross]

Steve,

I used the aluminized heat barrier cloth sold by Pegasus on my DB4. I've only done one test day so far, but it seemed to work well. I applied a single layer to the top of the left tunnel, and a double layer to the bottom of the engine cover near the header. For adhesive I used generous amounts of hight temp RTV. Let me know if you'd like some pics.

Rick

[Michael Cannon]

Steve,

You'll find what you're looking for here:

http://www.thermalcontrolproductsinc...roducts_id=156

[Steve O'Hara]

Hi Guys,

I found these folks last summer and they made me exact duplicates of the original Swift heat sheilds that fit above and below the headers on the DB4 using the ratty old parts as patterns. The cost for both pieces was $350 using the Nickasil(sp) .004" material which is more expensive but much more durable than the original stainless.

Advanced Thermal Products, Inc. Santa Ana, Ca
www.atpwrap.com
(714) 556-7252

These people were very friendly and responsive. I had the parts in about 5 days and they even put cool little stainless labels on them saying "made for Steve O'Hara"
I made one mistake.... I gave them the engine cover part and had it flattened out to make a pattern but did not explain that it had to have some bends so it was hard to manipulate from a flat piece since they had already folded all the edges. If you have them make parts send the stuff in the original shape so they can finish the edges in the final shape.

Regards,
Steve