I want to install some heat reflective matting under the cab of my '37 to help cut down on heat radiation. What I am looking at is a thin material made for 1500 to 2000 degrees with self-stick backing. Most of the sound deadeners / heat reflective mats go inside the body, but going under the cab, it should stop the heat before it can get to the metal. My concern is how well this type of material sticks. Will it be falling off after a while? The exhaust is fairly close to the floor and the transmission is really close. In 20 + years, the truck has been in the rain but a few times, so weather isn't much of a concern. Half the floor has thick padding under the carpet, but under the seat I put a thin layer of heater duct insulation.
If I wanted to insulate the floors of my car I would not use heat mat that's self adhesive. I would build heat shields spaced off the floor about an inch and install them over any heat sources. Then use the various heat mat material inside as it's usually done. I built a double firewall for my Austin gasser to eliminate heat transfer to the cab. It has a 1' gap, and the inside firewall is removable if I need to access the firewall. It greatly reduced temperatures inside the cab.
That makes better since, sticking to bottom might work for a while but most adhesives I have been around don't last forever. Time to break out the sheet metal again.
I put peel and seal from Lowe’s several layers thick on both side of my toe boards in the 46 and seam tapped the joints. It’s been close to ten years and it’s never even kinda losened. only place I’ve had it come off is inside the passenger side door where I just couldn’t get the old stuff off and cleaned well enough. The toe boards have been subjected to 100+ temps, rain, snow, and an obscene amount of motor oil. Never even had a corner peel back. I've also never caught any scent of it and its all over the inside of the car.
I don't know if any of you watch engine masters but I just watched it last night (season 8) and they did a test on 4 different mats designed to lower heat inside a car. Several interesting take-a-ways. .. 1- two of the mats actually raised the Temps by quite a lot !! 2- two others did lower heat, 1 more than the other. The best one was actually padded (maybe 3/16"?) It was worth like 40 degrees if I remember correctly. Another thing that was interesting is that they did the first one and thought they had installed it wrong as it raised Temps a lot over bare metal so they turned it around and the Temps were basically identical... so it seemed it doesn't matter which side the mat is on because it appeared that the mat worked the same way, either keeping heat off of the metal or keeping it from radiating from the metal.... ....
Since people have used heat shields above their headers to keep brake masters from boiling the fluid, you have to know it works. Dead air space between the shield and your floors is one of the best insulators around. That's why wood stoves use double wall piping to keep from catching the surrounding materials on fire.
Several decades ago, I worked for Aero Commander in their Bethany, OK facility. They were trying to get the new Turbo Commander certified and were having problems with the main gear tires catching fire when they were retracted into the wheel wells. The exhaust system from the turbine engines passed through the wheel wells in the engine nacelles of the plane. 3-M came up with a two-part insulation that when mixed, became a paste that could be applied with a spatula or putty knife. It expanded slightly while it was curing. If you applied a 1/4" layer of the raw insulation, it would expand to almost 1/2". When it was cured, a person could lay his hand on one side of the insulation and hold a lit cutting torch to the other side. I've done it and there was no noticeable increase in temperature. When we applied this insulation to the inside of the wheel well and the exhaust pipe, it bonded to the metal and was very difficult to remove. The temperatures in the wheel well dropped 1100 degrees F, and there were no more cooked tires. It's still available from 3-M as 3M Aerospace Sealant.
I installed 2 pieces of stainless sheet above the mufflers in my coupe. Wasn't much space, but managed to use a bolt through the floor, then a nut, then the sheet then a nut to hold the sheet. Not a big gap, between the sheet and the floor bottom, but enough that I could feel the difference.
When I built the engine cover/doghouse for my COE I used a heavy felt type material(like a 1/2" thick) with foil on the engine side. Used spray glue to hold it on and sealed the edges with high temp silicone. It killed ALL the heat from the engine/exhaust. Has held up perfectly for 8? years. Plan to use it again on my van engine cover
Embossed aluminium heat shield mat. It's designed for the job and available from ebay. Dimple the surface for screw fixing. Glue just acts as a heat path.
My Ford had a factory installed shield above where the stock muffler was located. It seemed to be able to pass air through it. IIRC, it may have been Longacre, they make stock car items. There were heat shield mats made to reduce cabin heat. Supposedly they worked well.
I used that spray on Lizard Skin. I really need to insulate the inside of the firewall as my whole dash would get hot. saw a demonstration where they had an electric hot plate at a show with Lizard Skin on one half and would put an Ice cube on the covered half and it would not melt
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