The Stovebolt Site Forums The Shop Area General Truck Talk Firewall Insulation

I'm still trying to find the best firewall insullation available to stop engine HEAT from coming into the cab of my truck. I would think there is a "pad" type of material that can be cut and applied that can do the job. Someone has suggested the same material that NASA suites are made of, but I don't know what that is. Others have suggested fiberglass with foil on one side. Can anyone tell me of a pad type of product that they have used that is a really good product they are satisfied with?
Thank you!

Joe,

I think welding blankets might do what you want and should be easy to find/get.

http://www.lonestarsafety.com/GroupInfo/GroupID/10927

Thanks, Curt!

how about dnynamat or lizzard skin. i have heard good thing about both and it is not to expensive. im planing on using both in my truck.

I think both are probably good for sound control. The web site on both products seems to promote the sound issue and hardly anything is said about engine heat. In my case, I really don't have a sound problem. I'm just getting too much engine heat through the firewall. I have to stop it in order to enjoy the inside of the cab on hot summer days.
Thanks!

I'll be watching this thread to.
My 350 sure does warm the cab up (won't need a heater core Ha Ha)

Reflectix [the bubble/foil sandwich] is good

Bill

Try an aircraft supply place. They make materials to protect the firewall.


http://www.aircraftspruce.com/catalog/appages/supersoundproofsheet.php

http://www.aircraftspruce.com/catalog/cmpages/divinycellfoam.php

http://www.aircraftspruce.com/catalog/cmpages/01-00488.php

http://www.aircraftspruce.com/catalog/eppages/shifterboot.php

If money is tight, buy the window reflector foil with the bubbles. Cost = $4. Just cut out the right pattern and you're done.

Reflects heat from the sun, should do the same for the firewall.

I think this is a good start for the reflecting or deflecting some of the heat away from the firewall. My thought would be to use this against the firewall metal inside and go over it with the welding blanket or something equal to that.
At this point, I think this is the direction I am planning to go in, unless I see something that changes my mind.
Thanks,
Joe

I used a foil covered insulation and noise suppressor. I covered My firewall, the underside of My instrument panel, the complete floor, and even under the seat with it...It is used in Cadillac's during production...A Engineer gave it to Me, so I don't have any idea where it can be purchased...Bill B

I've got a LOT of heat coming into my '46 from a 350 too. But the truck has no shift boot & has an opening for the master cylinder in the floor under the driver's seat.
Based on someone's (?) idea here, I intend to replace the floor "board" someone made it of 1/8" plate (heavy but no rolled edge so it doesn't sit flush with the rest of the floor!) with 1/2" or 3/4" plywood veneered with aluminum or stainless UNDER the floor. Then cover that w/lizard skin or the welding blanket above AND below held on with countersunk screws & fender washers. Same on the toe "board". What is everyone's opinion of these ideas? Too lumpy under carpet? If so, what seems to be THE optimum material/product for the inside below the carpet?

Be careful with moisture or you will have a mold problem

Mold? I have so much heat in my truck its hard to imagine it would EVER get moist. Of course I understand when it rains if the wood I'm proposing to use as a floor board gets wet it COULD rot, but when I run the truck I think it will dry pretty thoroughly. That said, it would probably be a great idea to treat that plywood with the same stuff they use on pressure treated lumber when you have to cut it.

I was just looking around and found this "shield" welding blanket. I like the looks of it because it has been used by NASA. I would think this thing should do the job. Anyone have any knowledge or comments?
Thanks,
Joe

http://www.sjdiscounttools.com/sti31646.html

I suggest looking up heat shielding on the Summit website or catalog if you have one. They have a few options of heatshields that are pretty thin but still have a high temp rating. The brands names are Cool It and DEI. I will be using something like this on my 39's firewall. I put a 350 in my 48 Fleetline and just used the cheap roll heatshield from a local hotrod shop and it does not do much to stop the heat.

thirtyniner

I have a 50 1/2 ton with 350/350 combo. I used dynpad $80 on top of Home Depot aluminum roof flashing (2) rolls @ $16 each. Just finished the install and went for a 30 mile ride. No heat! No noise! If you look up Dynapad on the net it gives a good description on how it works, Now if I had done this before $1200 on "Vintage Air"

If I was going to use plywood as a floor I would use MDO plywood.
it's not cheap but it is used for exterior signs and such.Probably $60.00 for a 4x8 sheet of 3/4 inch.

joetravjr, thanks for your experience and Welcome to the Stovebolt. I'm sure you will find some other bolters in your area. Just keep a watch out for them....but they may find you first!!

joetravjr,

Do you have pics of the installed material you did?

Sorry guy no pixs, but if you go into Home Depot where the roofing shingles and flashing are you will find rolls of flashing about 6" high and 20 " long. One side is a sticky mastic and the other side is aluminum. I've used this stuff on the inside of my doors so that they close with a nice "thud" and I've put it on the rear of the cab behind the gas tank. Keeps everything "nice n quite". The Dynamat site has good piks on Dynapad with details on what it does etc. The Dynapad cost a few bucks so I only put it on the floor. Before I installed it the floor was hot to the touch. Now it is much cooler. Hope this helps.

Joe Trav

What are the chances this stuff will come unglued? Always worry about it just making a mess everywhere.

I've had it in the doors for over a year, no problems.. This appears to be the same as Dynamat without the price tag. It is used for flashing around windows, doors, sky lights, etc on homes, sticks really well, no mess.

Thanks. I will go down to my look HD and take a look.

I used the bubble/foil combo from HD in conjuction with the jute padding & sound deadener from Classic Parts. Been thinking of going alittle further & wrapping my block huggers with some header wrap. Supposed to reduce temps under the hood up to 70%. That should help quite a bit.

Denny, the problem with your greenhouse test is you were heating the wrap as well as the metal with the temperature inside the bell - need to do it so the temperatures on each side are different as it would be with a firewall ... fer instance - replace the wood base with pink styrofoam, have the black metal flat against it, have a hole in the foam right under the shiney coated area - or flip the piece so the shiney stuff is up, exposed to the IR, and completely covering the metal and check the temp of the metal vs an uncovered piece

the primary benefit of Protecto Wrap and similar sticky construction materials for us is the prevention of condensation on the inside of the metal panel ... the thermal benefit will not be insulating against conductive heat transfer from the metal panel, but reflection of radiative heating by the shiney side, as in keeping the heat in, not keeping the heat out

Bill

Hi Denny,

It is great to have you back. I have missed your thinking outside the box approach and lively discussion.

Sound and heat insulation (in my x-spurt opinion) have different components.

The first component is direct transmission of sound and heat. All the holes and gaps must be filled. This includes even the tiny ones. This is a cheap and easy way to get a lot of benefit.

Sound insulation is improved by the installation of mass. For instance two layers of drywall in a home or a layer of limp mass vinyl http://www.auralex.com/sound_isolation_sheetblok/sound_isolation_sheetblok.asp will filter out lower frequency sound. The flexible flashing from a building supply store is an attempt at this. My question though is what if I or someone else want to remove this material in the future. It is an aggressively sticky product.

A third component of sound and heat insulation is dead air space. This is accomplished by the addition of fiberglass or welding blankets or bubble wrap.

Hate to spread around bad information. Best to listen to the experts.
DG