It might sound kind of funny to go to the great lengths to block engine noise and road noise from the interior of a roadster, right? Maybe we should think about insulation as a heat barrier that just happens to muffle any excessive engine and road noise at the same time. In fact, this triple layer of protection will not only remove almost heat transfer from the engine compartment, but it will also cut the noise factor down by leaps and bounds, no mater what you have under the hood of your ride. So why three layers of protection you ask? The simple answer would be, more is better, and as much as that is true in this case, the three layers used in this story also protect each other as much as they protect your ears and feet. One or two layers could successfully be used, however, the three layers protect and work together like no other combination we've come across.
To help illustrate ho these layers of insulation are installed, we once again look to Hot Rods & Custom Stuff (HR&CS) of Escondido, California, for some experienced help. After learning a little more about each individual layer of insulation in the following paragraphs, check our photos to see how HR&CS installs each layer. It's a pretty straightforward installation needing only a can of spray adhesive, a utility knife or industrial-type scissors, and a tape measure.
The first layer of thermal and acoustic protection comes in the form of a sprayable, brushable, or roller applied liquid called LizardSkin. Basically, it is a water-based ceramic coating with millions of tiny air filled ceramic and silica particles combined with acrylic binders. This means a reduction of at least 10-20 degrees or more depending on how thick you lay this stuff on. It's ready to be applied straight out of the bucket and it cleans up with soap and water. If that wasn't enough, you can even sand and paint right on top of it without loosing any thermal or acoustic performance. Hot Rods & Custom Stuff highly recommends coating the entire surface of a car's interior with LizardSkin and because HR&CS is an official dealer, they can either professionally apply it to your ride or outfit you with as many buckets as you can carry.
The second layer of insulation use here is another great heat barrier between you and your powerplant. Concours West, Inc., located in beautiful San Juan Capistrano, California, offers this ultra thin material called E.P.T. (Engine Heat Protection) Rollboard that has outstanding insulating value at temperatures up to 2,300 degrees F. This means up to a 50 percent reduction in heat from one side to the other. The Rollboard can be applied directly to body panels with contact-type cements, or as in our case, sandwiched between the first and third insulating layers. This stuff is so tough it can be sued as exhaust gasket material but is usually found lining the walls of high-end Bus conversions. Hot Rods & Custom Stuff installed the E.H.P. Rollboard with a strong 3M-spray adhesive directly to the fully cured LizardSkin, just under the cowl and firewall area.
As a last layer of protection in the crucial high heat, noise prone area of a hot rod, we find a product quite appropriately called The Insulator from Bonded Logic, Inc. Those at Hot Rods & Custom Stuff like this product not just because it looks cool but more importantly because it acts as a heat, acoustic, and fire barrier. For our purposes we chose the dual-sided sheeting. Between the aluminum foil outer layers is a layer of natural fibers treated with a natural fire retardant. It is "flash-dried," which gives it a Class-1/Class-A fire rating. Another issue you won't run into is itchy fiberglass like particles flying through the air every time you cut into the sheet. This stuff cuts easily with a utility knife or industrial-type shears, and when finished off with either the aluminum tape offered by Bonded Logic, or another comparable aluminum type of tape, it forms a superior barrier of moisture, heat, and noise that will last just about forever. Check out how it all went together SR