In http://www.instructables.com/id/Removing-internal-auto-trim/ I showed initial steps I took to add some sound deadening to a diesel Ford Excursion. It's a loud car; the 7.3l diesel engine exhaust could definitely use some muffling.

In this -part II- I'll show how I laid self-adhesive aluminum/butyl mat over all the sheet metal in my car's cargo area. I covered that first layer of sound deadening material with a glued-down sheet of ensolite foam to absorb yet more sound energy.

I laid down a double sandwich of those same materials on the floor. Per advice from an expert, Rick McCallum of http://www.raamaudio.com, doubly covering the floor will help most with blocking out sound from under the vehicle.

I also used expanding polyurethane foam to fill in some huge and undoubtedly resonant voids inside my truck's body panelling.

I understand that most people who go to this amount of effort with sound deadening do it for car audio reasons. My primary intent with this project is simply to quiet the interior of the car.

Step 1: After cleaning and prep (see part I) I laid down acoustic deadening mat.

I took out all interior trim up to the headliner, cleaned and prepped and then started covering all the exposed metal surfaces I could with acoustic deadening mat.

I used tools I already had on hand. I purchased sound deadening materials from http://www.raamaudio.com and my local Ace Hardware store - please see http://www.instructables.com/id/Removing-internal-auto-trim/ for a full tools and materials listing & some costs. So far the total spend is a bit over $400 and many hours of work.

Here are the sound deadening materials I applied...
You can also use roofing patch material.&nbsp; It's basically the same thing.&nbsp; Get it at HD or Lowe's.&nbsp; <br /><br />You used far more foam than you needed to.&nbsp; All you have to do is dampen the vibrations on the big flat(ish) metal panels.&nbsp; The obvious big panels are the trunk and the hood.&nbsp; The side and door panels come next and the roof if you can get to it.&nbsp; The flooring is a big panel but it is usually formed to stiffen it.&nbsp; All you need to do is stick a couple strips of of the aluminized tar paper or a couple lines of foam in an X pattern.&nbsp; What you did will work but it's just a waste of foam.&nbsp; <br /><br />Another approach would be to use a heavy adhesive like that used to hold lineolium flooring down.&nbsp; Apply it with a slotted adhesive trowel.&nbsp; This would leave the panel covered with a pattern of stripes.&nbsp; When they dry they will help damp the vibrations across the entire panel or where you can reach.&nbsp; <br />
<p>Applying Roof Strips from Home Depot cost me about 450 bucks and more time than I care to spend. After I did damn near my whole exvursion, it got hot in town and that stuff was off cgassing like hell. Do you have ANY ($&amp;%Y#W*@) IDEA HOw hard it was to remove it from the entire floor, all four doors? Took two mexicans two days, and my wife and I another two days, then about another 4-6 days of cleaning TAR crap off the car. Not to mention I had to find something that wouldn't kill us to clean it. If you value your time and life - don't use a roofing product - PERIOD. Oh, I had to clean and relay all the sound deadner twice becuase someone sauid - yeah it's all the same - Negative. Asphalt is Tar based. BUTYL is rubber and has no residual.</p>
<p>Sorry - didn't mean to go crazy, just it was a bad move. This truck is moslty for families and don't want to kill our kids with poisoinous gasses. Maybe for a 20 year old with a civic, but doesn't do justive for the X. I think you are right on the Expanding Foam. I did not fdo that in mine as I felt I wanted to keep only automotive products in mine. I used SEM auto Sealer for all joints int he car and really went overboard in compared to yours. After I did the Asphalt and then ripped it all out, we cleaned the tuck dowbn, but to remove the tar, it took all the caulking and factory sound proofing out. So I recaulked all corners, etc with the SEM Seam Sealer (AWESOME Stuff!) then went with a liquid lay down of GT Sound Control Liquid Sound Control, then TWO layers of 80 MIL Butyl, then another layer of liquid. I also notice my excursion did not have the insulation pieces over the wheel wells, so I went to a junkyard and got those. I moved the AC, did behind there, added close cell foam, etc... Ugh... It has been 7 months. My wife wants her truck back.</p><p>This all started with - Honey, can you put speakers in the truck!</p>
Thanks for the comment - but with respect, roofing patch material is NOT&nbsp;the same thing. As you note, it's tar based- as a result, it stinks mightily and will melt &amp; possibly&nbsp;slip around in very hot weather. <br /><br />I&nbsp;agree that&nbsp;it could be used, as could tile mastic or other flooring adhesives, and I've read at least one writeup that mentions someone having used&nbsp;roofing tar sheets&nbsp;extensively. Probably would have been much cheaper than what I&nbsp;used...<br /><br />But, but, but&nbsp;- the RAAMmat&nbsp;I&nbsp;used is specifically designed for auto sound deadening. There was&nbsp;very, very&nbsp;little odor, and it's&nbsp;tacky butyl rubber with&nbsp;an adhesive layer under soft aluminum composition won't&nbsp;melt and run or possibly even slide completely off in hot weather. We regularly have summertime heat reaching 110+&nbsp;for weeks on&nbsp;end where I&nbsp;live, so that was a big consideration.<br /><br />I&nbsp;hear the &quot;too much foam&quot;&nbsp;part of your comment tho, and I&nbsp;completely agree. :-\<br /><br />&nbsp;I&nbsp;was however trying for *as much sound prevention as possible*, and I think the overfoamkill and completely covering all panelling with at least two deadening mat layers is definitely accomplishing that. Panels and areas filled with it sound *solid*&nbsp;when knocked on now, versus a hollow echoing tap coming back from unfilled areas.<br /><br />I'll run out of materials before I can get to it, but the roof and panels inside the engine compartment like the hood are likely suspects for future parts of this extended project. <br /><br />Thanks again for your comment - good ideas and alternatives!
I worked for an appliance store many years ago. Whenever they bought a new van, they'd apply mastic to the floor, then stick cut-to-fit 1/2&quot; plywood to it. They did it to strengthen the floor, but I'm sure it quieted the vans down as well.
<p>This is awesome, thanks so much for your photos &amp; comments in the photos. Do you think the spray foam made a significant impact on sound reduction? Once the aluminum/butyl mat and the ensolite foam is applied, I'm wondering whether it's a matter of diminishing returns when applying the spray foam? Given the amount of effort required on the spray foam, do you think it was worth it, in terms of additional sound reduction?</p>
<p>Definitely a worth project. Have you finished it yet?</p>
<p>Thanks for the instruction. I am about to do something similar with my 81 1.9l turbo diesel AAZ swap VW Truck as well as my 77 TDI swapped Rabbit!<br>I beleive I may go with #2 marine foam, though. </p>
I have been meaning to put a <a href="http://audiotechnix.com/" rel="nofollow">sound deadener</a> in my car for ages but have never gotten around to it. I think that I will try to get the materials today and tomorrow and install them on the weekend. It will be so nice to drive without all of the added road noise. It will also me nice to have better audio inside the car as well.
HILTI makes a foam product that might work better in this project. First it is hydrophilic, and cures by sucking moisture from the air. Second, you have about a month to use the can- instead of about an hour with the Dow brand. This means you can put layers down and not worry about buckling panels. <br><br>You can get it through Hilti, or you can get it at home depot. It's called cf116. Home depot only carries it on the shelves in larger stores. The other stores can order it through the pro desk or you can check home depot online.
expanding foam will just trap moisture and create rust i just had to replace the rocker panels on my truck because the previous owner thought great stuff would be somehow helpful inside the truck. the foam came out shaped like the inside of the panels and the panels fell apart in my hands. i was reading today about some marine stuff that they use for soundproofing motor covers on boats. something like that might work well. and be cheaper then the brand name automotive stuff.
i'm interested in your sound deaadening project on the ford diesel.&nbsp; i have a similar ford diesel.&nbsp; it too is very noisy, 95dbs going down the highway at 60mph.&nbsp; did you check the dbs of your ford before and after you finished the project?&nbsp; i would really like to know how successful you were at reducing the dbs at free way speeds.&nbsp; i'm not into doing the project myself and upholstery shops cost a lot and have no before and after comparisons.&nbsp; i would really like to know it is going to help before i spend a lot of $.&nbsp; regards bob&nbsp; trebornoom@gmail.com<br />
I can't offer before/after decibel readings, unfortunately - I don't have a sound meter.<br /> <br /> Just doing the cargo area and rear side panels&nbsp;yielded &quot;noticeable&quot;&nbsp;results, if that subjective analysis does you any good. '-) I feel strongly that even the project so far has been very well worth the effort.<br /> <br /> I&nbsp;haven't had time yet to complete the project with deadening under the 2nd row seating and forward; so far I only also have the left rear passenger door sound insulated. Given how much quieter the rear of the car is now I'm really looking forward to getting the remaining floor and doors done. <br /> <br /> Watch out for keeping lock rod travel clear when doing doors... Mine is sticking somewhat on remote control, tho manual operation&nbsp;is fine, and I've got to get back in to free it.

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More by kerns: Auto sound deadening - part II - more matting and using expanding foam Auto sound deadening  - part I - remove trim, install some matting. Repair / join strapping with zipties
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