Dynamat Ideas

Discussion in 'General Chevy & GM Tech Questions' started by GrizzlyTN, Mar 1, 2012.

  1. GrizzlyTN

    GrizzlyTN Rockstar 100 Posts

    Hey guys, I'm wanting to use dynamat or something like it to dampen some of the sound. My sound system rattles the hell out of the inside, and my mud tires don't help much for quiet ride.

    I want to insulate the floor, the doors, the roof and possibly the backwall behind the seats.

    I have NO clue how many sq feet or sheets that's gonna be?
  2. ahmitchell1

    ahmitchell1 Rockstar 4 Years ROTM Winner 1000 Posts

    A decent amount. If u can use lizard skin it's amazing
  3. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    I used RattleTrap Extreme (80 mil) to cover:
    • Roof (arguably the most sound reflective surface in the cab)
    • A-pillars and B-pillars
    • Rear wall
    • Entire floor
    • Both kick panels
    • Outer door skin for all four doors on extended cab truck
    • Inner door skins for all four doors on extended cab truck
    • Mirror mount locations
    150sq. ft. fell just shy of being able to do all of the above -- and I was very precise in my cuts. I then ordered another 50sq ft. so that I could finish up a door I didn't quite complete and then cover/dampen:
    • Every metal-on-metal and plastic-on-plastic mating surface in my full center console
    • The interior, under side of my dash (this had to be done in pieces due to opening size, as I didn't remove the dash)
    • Behind driver's side knee panel (including metal struts against which the panel rests)
    • Back side of gauge cluster
    • Behind passenger side knee panel (around glove box and including metal struts against wihch the panel rests)
    So, I used 200 sq. ft. of the stuff... and I have exactly one minor rattle left to chase down and probably 7 sq. ft. left. The sq. footage requirements are why I chose RattleTrap Extreme over Dynamat .... as it's less than half the cost per sq. ft.

    Pics of my roof, floor, rear wall, and the inner skin of my driver's side door can be found here: http://www.gmtruckclub.com/forum/album.php?albumid=18156
    Last edited: Mar 1, 2012
  4. GrizzlyTN

    GrizzlyTN Rockstar 100 Posts

    Sounds like you did it All The Way man! I doubt I'm gonna tackle doing it myself, it would take a long time and I know I would break all kinds of plastic tabs and clips in there!

    I'm thinking I need about 100 sq ft for a regular cab?

    I'm probably going to have the interior door panel but not the exterior one, they said it would cost allot more because of time/labor.

    Any other spots to double layer it besides the roof?
  5. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    I wouldn't double-layer the roof. A single layer is enough and the sq footage of the roof is very large, so doubling there would be more costly than doing the doors inner and outer skins. In my opinion you absolutely should do the inner and outer skins of the doors; that's how the pros tend to do it and it's going to give you reduced rattles AND reduced exterior noise (which means a cleaner listening environment). The outer skin was actually far less time to do than the inner skin, by the way ... as you don't need to be nearly as precise because you're not routing around wires, door locks, etc.

    The cab vents on the back wall are places to make sure you are thorough, too, as they are the cause of a LOT of external noise. You shouldn't seal them up completely since they exist to allow air to escape the cab in the event of an airbag deployment ... but you can certainly adjust their size by layering over sections of them if you're inclined to do so.

    You can make do with 100 sq. ft. but you won't get your dash innards done that way ... or your pillars ... or two layers on the doors. I'd error toward 150 sq. ft. if you're going to lay it down with precision and have no gaps between pieces ... which is a must on the rear wall, roof, floor, and inner door skins.


    P.S. I spent the better part of 80 hours doing mine. A local shop had estimated 60 hours at 50 bucks an hour. That's 3k in labor that I saved using their estimate. I broke a few clips, too, but those are cheap compared to 3k in labor. I also had a really good time doing it as you might have seen by the pics of the lawn chairs I put in the truck for fun once I had the entire interior removed from the truck. :)
    Last edited: Mar 1, 2012
  6. The Heater

    The Heater Rockstar 100 Posts

    Hi, GrizzlyTN:

    Do the floor, then see how you feel about the noise reduction. You may want to add a layer of sound material on top of the Dynamat. LMC sells insulation covered with reflective foil on both sides, with fiber insulation for sound proofing in between, about an inch thick, at least they do for my 94 truck. Check out LMC and see. Otherwise there are sources, such as Summit Racing and Amazon, that sell ThermoTec and other types of insulation like this that you can order in bulk and cut to fit your needs.

    The floor transmits the most noise. Dynamat it, and add that extra insulation, and you have most of your noise reduced. Make sure you go up part of the firewall if possible. Next would probably be your doors. However, doors are a real challenge to remove the panels and then the sub panel to get the window mechanism out to Dynamat the door skin. Not worth the time unless you are painting your truck and want to take off the doors. That is how I did it (well, the body shop did it).

    Dynaliner works well to put over the Dynamat if you do the roof. Use the quarter inch thick stuff. I did it and the headliner still fit over it fine.

    You can also do the back wall of the cab with Dynamat and 1/2 inch thick Dynaliner.

    Some interior panels will take the 1/4 or 1/8 inch thick Dynaliner. Dynaliner is very light weight, not like Dynamat. Check for clearance between the panel and the bodywork.

    That LIzardskin paint works well, if you have the interior out of the vehicle and you want to mask off everything you don't want to hit with it. But I think unless you are doing a frame off restoration of a vehicle, it is not practical for most people.
  7. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    That's absolutely un-necessary. The door panels take a whopping 3 minutes to remove if you know what you are doing ... and maybe 10 mins if you have absolutely no idea what you are doing and are being careful. (And I'm fairly certain you can google and find a video or photo log of how to do it to shave that down.) Once the panels are off you should have no need to remove the window mechanism, as the opening beneath the plastic is large enough to allow you to work through it. Simply measure, mark, then prep pieces you can fit through the opening, emplace the pieces one at a time, remove the backing, and adhere it to the appropriate spot -- then apply pressure with a roller and use a heat gun as appropriate to get the adhesion you want.

    I managed to do the outer skins in two large pieces for the driver's and passenger doors ... which I heated with a heat gun slightly to make them more pliable ... then rolled, placed through the opening, unrolled, removed the backing, and stuck it into the location I had previously measured and marked with a paint pen. In the extended cab the rear doors were even faster, as the opening is even larger than for the front doors.

    The outer door skins were actually among the fastest things I did during the installation...
  8. zigger215

    zigger215 Member 2 Years 500 Posts

    ...doors take seconds to pull off on our trucks. Windows don't need to come out to dynamat them either and you can pull off the moisture barrier and put it back ok easy enough. Definitely put that **** back on lol
  9. The Heater

    The Heater Rockstar 100 Posts

    Hello, Surreal:

    I think you misread my statement. What I was saying is the sub panel is hard to remove. In order to remove that from any vehicle that has it like on my truck, the entire window mechanical assembly is mounted to the sub panel for mass production reasons. They put the entire assembly in, with the glass, at the same time. To remove it, you must do the same thing. Trust me, I know, I did it on both doors when the truck was disassembled and the doors were removed. This has to be removed to put sound deadener on the inside of the door skin. There is no "hole" as you describe that would give you access to that sheet metal, because the window mechanism is in the way, whether the window is up or down. You might get a small patch installed but that is it.

    What you appear to discuss is putting Dynamat over the sub panel, or what you call the "outer skin". Sure, Dynamat has pictures of that. On my truck, you would be a fool to try to cover this because there are too many attachments to it. You truly would be a moron if you thought you could somehow cover the real door skin on the inside by simply taking off the interior door panel.
  10. dualdj1

    dualdj1 Rockstar 100 Posts

Share This Page

Newest Gallery Photos