MTFCA Forum

Is anyone using a heat insulation product such as Dynamat to insulate the underside of the floor boards? Does is make any sense to do so?

If you are thinking of preventing exhaust heat coming through the floor, what you really want is a double layer of embossed aluminum heat shield under the floor. Don't use the stuff with a layer of fiberglass in it, as it can soak up oil and become a fire hazzard. Use the plain metal sheets, and double it up to create an air-gap. It's easy to find on ebay.

Adding shielding inside the car doesn't prevent the capacitive effect of heat soaking the floor.

Good thoughts on the aluminum heat shield. Did you use screws to attach it to the plywood?

I haven't used it on a Model T yet, but I will use screws and keep in mind that the boards will need to be removed. So I'd install it in overlapping sections so the boards aren't all fastened together.

I have used it (and about a dozen other types of heat shield products) in my day job of building racecars.

What heat source are you trying to block off? Engine, exhaust, other ??? It will only make sense if the solution provides more comfort than it costs.

I've used this quarter inch roll insulation between the floor mat and floor boards. Seems to block heat, fumes and noise. It's inexpensive, cut with scissors to fit. If you like, you can spray the aluminium black where it shows around the pedals and starter button.

https://www.homedepot.com/p/Reflectix-1 ... /100012574

Would a solid insulator work? I use an item called Hardy Backer when I am using a torch for soldering jewelry.
I took an acetylene cutting torch to some one time to see if it would burn or break down, it did not. After having a butane torch against it many times I will develop surface cracks but that would be a lot higher temperature (1300 to 1400 degrees) than what you would have coming off a model t exhaust system..
I get it at Lowe's for less than $20 a sheet. It is quarter inch thick and I think 3x5 feet in size..it is marked on one side in 1 inch squares and can be cut with a hand saw. To attach it I would drill holes in it and use a body washer on the screws attaching it for more support. It is designed to use as a backer under floor tile. Tile shops should handle it also.
It does not let heat thru as I use it on a glass top table when I silver solder.