I just pulled out all the factory sound/heat deadening from a project because the heater core leaked everywhere and I’m planning to replace with the butyl rubber based sound deadening that’s the current norm (Dynamat or equivalent, I’ll probably use the Amazon version). I have had a bad time in the past removing this type of stuff if/when it gets wet. Chipping and scraping it off isn’t fun, especially when it’s soaked in coolant. So do you really have to stick it on? Or can I just sandwich it under the carpet, maybe peeling off a few corners here and there to keep it in place? I can’t imagine it making much difference but I’m no expert at sound resonance and heat transfer…
Take the time to do it correctly. More work for certain, but halfway measures mostly come back to bit one in the posterior!
Firmly adhering the sound deadener to the panel is part of how it works. Not sure how coolant would react; but I managed to spill about a gallon of water on the Kilmat in my car and it didn't seem to bother it any.
I assume you replaced the heater core therefore, it shouldn't leak again for many, many moons. If the Kilmat is adhered properly to the metal (even if the heater core leaks again), you should be able to wipe down the foil with Simple Green or equivalent and carry on. My floorboard with Kilmat........
Take a pie tin and hold it horizontal. Flick it with your finger. Set a pot holder inside it and flick again. Spray glue on the pot holder and the tin and stick 'em together. Flick the combo. If you are smart, you know the answer without having to glue them together. If you need proof, this should show you why. BTW, 6 comments in 15 years!?!
The butyl type stuff needs to be adhered to the surface in order to work since it adds mass to the panel to dampen its vibrations.. You don't need to cover the entire floor (or door, firewall, etc) with that stuff, though. Only specific locations such as in the middle of the footwell would need it. If you look at photos of modern vehicles and how the material is applied in them you can get an idea.
Thanks everyone, I will stick it on and leave some channels to drains incase of liquid leakage/spillage. But thousands of threads read!
I called Dynamat's tech line when I was finishing up the interior on my 1936 Ford cabriolet. They told my Dynamat is a sound deadener and must be adhered to the metal to work properly. Dynaliner on the other hand is a thermal barrier and it did not have to be adhered directly. I wanted to layer both so I glued the Dynamat directly to the floor but glued the Dyanliner to the underside of the carpet (all of my carpet snaps in place and is removable). My buddy asked me why I didn't just glue the Dynaliner to the Dynamat and the only answer I came up with is because I am weird.
Sound is made by vibration. Adhering the material cuts it there. To imagine an extreme,,, when firing a shot gun you want the stock tight to your shoulder.
Not adhering the stuff can help to slow heat transfer as it can slow heat transfer by conduction. For noise dampening, you want the stuff adhered. For heat dampening, less connection is better. You must have taken a heat transfer course in a prior life, because you did it right.
If the butyl sound insulation is adhered to the metal, the coolant can not get between it and the metal, so there would be no reason to remove it. The butyl that sticks to the metal does not "collect" water (or antifreeze, or oil) and if stuck and pressed against the metal, it will not let the coolant (or anything else) to get in between it and the metal. You would just need to wipe down the foil surface.
I buy the foil backed dense gray foam insulation for air ducts. It's made by Frost King and cost me $16 a roll for 15 sq. ft. last batch I bought. Two rolls did my coupe with double layer on the firewall. Self adhesive and even if it gets wet it wont get through the foil or need replacement.
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